The Izzet tempo deck is very much an established, commonly seen, tier one archetype in any flavour of cube. They are deceptive decks to draft and build and people often get them subtly wrong. There are two reasons you go Izzet tempo. The first is that you were going for a red deck wins list but didn't wind up with enough playables to go mono red. You can pair any colour with your failing RDW list and it should mostly be based on what lands you are seeing/have already. As such you see more RwDW and RbDW than Izzet "failed RDW" attempts based on the popularity of the lands. The second reason to go Izzet tempo is because it is really really strong in the hands of an experienced and skilled player. You have far more control over the game and can compete with a far greater range of things. While there is plenty of playskill in a simple aggressive RDW list you are rather at the mercy of your opponent not doing anything you can't handle. The Izzet player has a much more even spread of matchup win %s than RDW. It has no auto wins or overly tough games. Izzet also has far more scope to be tailored to cope with any given meta or archetype than you do with a simple red deck and it typically copes fairly well with things going in blind. A good RDW list in the hands of an average cube player might have say 55% on average across the meta. That same player would have say a 50% chance on average across that same (infinitely broad for the sake of argument!) meta with an Izzet tempo deck of the same quality as the RDW lists. A good cube player might only improve the win % of the RDW in this example by a couple of % however they will be able to make that much more of a difference to the Izzet tempo decks win % across the meta that it has a higher overall matchup against the meta and is the better choice of deck. It would be very slight, say RDW at 57% in the hands of the good player and Izzet tempo at 58%. The significant thing is that going from average to good only offes a 2% rise in the RDW list while it offers an 8% rise in the Izzet tempo deck - four times the scaling with skill! The numbers I randomly chose to illustrate a point worked out neatly!
So, what is the key difference between RDW and Izzet tempo? What is it that makes some cards transfer from one list to the other brilliantly while others transition less well. That is a key point to note, do not assume just because a card is powerful in RDW that it is also good in Izzet tempo, a lot of them are but certainly not all of them. The archetypes are similar, they want a lot of the same cards and that is missleading. The similar element between the two archetypes is that you have burn for cheap efficient tempo removal and reach combined with cheap threats. That is about where the similarities end. RDW is all about redundancy, everything is doing damage and everything is pretty direct. The Izzet deck is far less about redundancy. It thrives on little bits of exotic spice! Izzet decks play less threats and less burn than RDW lists, they fill in these gaps with card quality, card draw and other value cards and some mild on theme disruption.
The trick with Izzet tempo is to have really premium things. This sounds dumb as obviously every deck wants the premium things. A better way to put it would be to say that the range of ratings on cards you might want it typically much greater in Izzet tempo than for RDW. The Monastery Swiftspear is worth more to the Izzet player than the RDW player while the Falkenrath Gorger is worth less to the Izzet player compared to the RDW player. These ratings changes are fairly minor but they depict what I mean by the premium stuff being more important. The same is true of burn, RDW is happy picking up any one or two mana burn spell while the Izzet player will be more choosy. The thing that makes picking premium cards extra hard for Izzet tempo is the importance of lands. You want every dual land on offer and the ones that come in untapped, particularly those than can give any colour on turn one, are some of your highest picks and most important cards. An Izzet tempo deck is very cheap and thus very colour intense yet it is also two colours and relies on tempo. A bad mana base kills an Izzet tempo deck. RR and UU cards are much weaker than usual because you are that much more constrained on colours than usual.
So what do I mean more specifically by premium cards? A better way to think of this is high impact cards. The deck thrives on cheap things but it wants cheap things that scale well into the game, it wants every one of its threats to actually be a threat if possible. Efficient generic beaters are OK filler, what you really want are the things with evasion or great scaling with your various effects. The best threats are the ones that can win a game all by themselves if they stick. There really are not than many cards in the one and two slot which deserve that high acclaim! Never the less, those are the things you need to have a half decent deck.
This is true of burn too but to a lesser extent than the threats. Cheap burn is super important so that you can keep up the tempo, applying pressure and removing things all at the same time. High impact burn is also of great value as you will have less of it. Doubling up on burn spells to deal with something is harder and more painful in Izzet tempo than for RDW. As you may well have recursion effects the better your cards are the better they scale with the recursion. The more important it is to have your cards be cheap so that you can quickly reuse them. When you have to use card quality and draw to dig into your burn you will have used extra mana in effect on top of the cost of that burn spell. If the burn spell costs too much you will fall behind in tempo or not be able to play it.
In a previous article in this series (I think the UW control one) I mentioned that different archetypes will see a wildly different % of the cards in their deck in any game they expect to win. An aggressive deck will see far less than half of its cards for the average of its wins. A control deck and many combo decks will see far more than half their cards in their average wins. The archetypes which see less of their decks like redundancy more. Those that see more of their decks are much more sensitive to changes. The performance of such a deck will have a much higher change in win % as a result of changing one card compared to the aggressive decks. Izzet is generally an aggressive deck. It has control elements but they are used to keep you ahead in tempo specifically rather than generally control the game. The disruption of the Izzet player is more akin to that as used by the combo player than it is to that of the control player. Sorry, got distracted and went off on a tangent! The point here is that Izzet, while an aggressive deck, should expect to see a high % of its deck in any given win, more so in the losses. It is an aggressive deck than it incredibly sensitive to build tweaks. I have had several games as an Izzet tempo deck where I used every single ounce of threat in the deck to close the deal. This is one small example of the skill intensity of Izzet prowess. If you cannot easily recall the cards that are left in your deck at any given stage, at least the relevant ones, you may struggle with the deck. If you know you are running light on remaining gas you might need to play differently to get more done with what you have. Plan wrong or judge the situation wrong and you can be in that awkward spot where you get them to one life and have no cards left but lands, card draw and perhaps a counterspell...
So how does Izzet tempo play different to RDW? Mostly it is in the control over the pace of the game. The RDW player plays as quick as it can go or is allowed to go. It may slow down to respect a Wrath if the game gets to the midgame but the general rule of thumb is just getting them dead asap, making the highest damage output dorks first etc. It is usually pretty clear when to burn a path for your cheap threats and when to start aiming face and chump attacking. In Izzet tempo you want to almost taunt your opponent with just being that little bit quicker. You can let them outpace you in the early game in some cases if you have a way to swing the tempo back and finish the race ahead. You can just stay one relevant threat ahead the whole game. Against a number of control decks you are literally happy to roll out one proper threat at a time so as to negate the value of mass removal. Not only is this painful for them but it is required for you, if you lose too many of your good threats to a single wrath you may well not have enough to close the game. This is not to say you don't wind up going all in and rushing a sprint finish loads with Izzet tempo, you do, but it is a calculated choice based on the specifics of that game. It is not the normal course of play.
A little like the cheat in archetypes the Izzet decks have a selection of synergies most of which overlap. Not being a combo deck the synergies in the Izzet lists are much milder but it still pays strong dividends to pay attention to them. As you pick up top quality cards that work with other thing the value of those other things will increase. It is important to know which things you are digging for and how your priorities should be shifting as your draft progresses, or as you sculpt a deck for a known meta.
Izzet tempo decks want a more curved mana curve than most other decks. I am happy playing five drops in my deck, I actively want some four and five drops in my lists while I feel the best aggro decks in other colours are those that skip those mid level points in the curve all together. You want a massive amount of one drops in Izzet prowess and you are happy to go to five, as such you tend to thin out much quicker than other decks on each subsequent rung. Even two drops can feel slow and clunky in Izzet tempo decks! A nice example curve would be 13 one drops, 6 two drops, 2 three drops, 2 four drops and a single five drop. Despite there being such a high number of one drops they will be fairly spread between creatures, burn and card quality, perhaps a disruption effect or two. You will probably have only five proactive threats at one mana, more would be lovely but playing bad ones to get above this number isn't great. You usually have to play a couple of decidedly average ones just to get to five! Five one drops threats, perhaps four two drops threats and at least another three threats from the three CMC and higher brackets. That would be a nice healthy threat count.
One CMC Threats
Delver of Secrets 9.5
In the god deck this is the best threat by a good old way. In the more mediocre decks this is probably worse than the other good threats in the list. Your count of cards that flip this combined with how much effective manipulation you have to turn it on define how strong it is. With 12 things that flip it and say four good enablers including Brainstorm then Devler is the thing you want to make on turn one. They need to kill Delver else it will do critical damage quickly and reliably. Not much can block it. Not much at all before turn four can block it and live to tell the tale. Three power one drops are well known for being very potent however Delver goes above and beyond the likes of even the mighty Wild Nacatl, especially in this archetype. As a flier it can simply ignore a great number of things. Your opponent is under pressure to deal with it yet most of their defensive creatures will not interact with it. This allows you to free up your disruption and removal and then consequently your mana to do other things.
Cloudfin Raptor 9.5
Incredibly good card and somewhat underrated. In the right list this is your best one drop however in my experience in the best lists this isn't quite as catered too and is much closer to Swiftspear in value. It is a shame this scales badly with the things Delver scales well with and vice versa. You cannot easily have both being insane. Raptor can be a bit rough as a late game topdeck but usually you have enough filler and card quality to mitigate this issue. A turn one Raptor is quickly and reliably a flying Kird Ape. It dominates the skies more than Delver, is a little more robust to removal and can occasionally turn into a truly beastly 3/4 or even a 4/5! A touch slower than Delver but far more consistent overall.
Monastery Swiftspear 9
Great little card that is hard to get into combat with early and that gets in a whole load of damage, timed as you need it. The one issue with this card in the deck is that it has no evasion. Many decks will simply make stuff so big even if you could make Swiftspear bigger with prowess you would have blown your load and have little else going on. Your highest impact card in the early game or in low economy games but falling off in power and effectiveness much more rapidly than Delver and Raptor.
Goblin Guide 8.5
A chunk worse than Swiftspear in this archetype. Games go on longer so the card disadvantage is worse. You have the support to ensure Swiftspear does more damage. Guide is just a card that is so good that you are quite happy playing him despite being more off theme than you might think. Guide is worse than Swiftspear early in the game and gets worse quicker still than the Swiftspear. No evasion, no scaling, no extra synergy. Just great because it is super cheap and fairly often does more damage than you should be able to do for one mana. When your plan is to take the tempo there is little more reliable than a Goblin Guide to do that for you out of the gates. The best one drop you can have in a weak draw and still in the top five one drop plays for a nice complementary hand.
Stromkirk Noble 8
Oddly this is a card that jumps wildly up in value between RDW, where it is an OK card, and Izzet tempo where it is a good card. It many ways it is better than Goblin Guide. It is certainly something I would rather make on turn one. The issue with Stormkirk in RDW was always such a limp card when you didn't make it turn one or two. That issue is doubly less relevant in Izzet prowess. Games are typically longer so later is fine and if not you still have looting and card quality effects to turn it into other gas. Noble has some mild evasion and he also has a higher chance of winning the game basically by himself than Goblin Guide does. Tap, bounce and pump effects improve Stormkirk as they allow you to grow him into more of a threat in the midgame compared to burn. Stromkirk is a card I want in Izzet tempo while it is a card I don't want in RDW if I can avoid it. The best versions of RDW don't contain him while the best of Izzet prowess do.
Grim Lavamancer 7.5
Great card with lots of great synergy in the deck but also some drawbacks. All your delve, flashback and recursion effects don't appreciate Grim Lavamancer chewing through all their targets and fuel. Grim Lavamancer can be great card advantage and is a nice evasive threat than can help close out a game that would otherwise be in stalemate. Grim is also a low tempo card. Even if you make it turn one and can kill relevant things with it from the next turn you are still not proactively winning the game. Lavamancer is better with a lot of looting effects as these ensure you have lands in the bin as well as just burn and card draw things. A great card in the archetype for sure but one that requires far more consideration in your other picks and final build. It may cost one mana but it is not the ideal turn one play, just better than doing nothing.
Zurgo Bellstriker 8
This guy is actually quite a bit better than most of the other filler one drop dorks you can play. There are several aspects where Zurgo outperforms Golbin Guide. He doesn't give away cards which is always nice, he also is one of the few threats you have that gives some protection against mass removal. Late game when you have mana spare you only want to dash Zurgo. Not only will this make him harder to kill but it is extra red spells for your flipping Chandra! This is your other Goblin Guide and due to their not being enough purely on theme one drops you do always want the best of the filler one drops of which this very much qualifies as.
Phantasmal Bear 7.5
This is generally better than the various red 2/1 dorks you can play. It is more robust in combat and gives more flexibility on mana in the early turns (as most of your one drop dudes and removal are red it is very nice to be able to spend a red and a blue on turn two and do two things that both gain tempo). There are some free ways to kill this but not loads, a lot of them kill a 2/1 anyway! The fact that this is only one mana means that a lot of the time even if your opponent does kill this without costing them a card to do so you are still a long way ahead in tempo from it. If it deals 2 or 4 damage and requires a sub par play or even just two mana to remove it you are very happy with things despite being a card down.
Falkenrath Gorger / Satyr Firedrinker / Rakdos Cackler 7
These are the real filler cards. You need a certain mass of cheap threats and if you don't get the on theme and powerful ones these will do just fine. Ideally you want five or six one drop threats and as far as I can count there are only seven good or on theme ones including Grim Lavamancer which isn't so much on the proactive side. This means unless your draft goes perfectly you should expect to be picking and playing a card or two like these. Just aggressive one drops. They will get in for a bit, apply pressure, give you some consistency in the early game but they will hurt you more in the late game where they offer no reach and pathetic power levels. The more of these cards you have the higher the value of looting effects. One of the hard things about drafting this archetype is when you are faced with a pick involving a card like this early. You don't want to have to play them however that pales in comparison to how much you don't want to not have enough one drop threats come the end of the draft. You have to weigh up if you want to potentially pick up a dead card just as insurance on not seeing the things you want to play over it. Generally I find it is right to play safe and pick the one drop. The real issue is when it is something like a Preordain against your Firedrinker. Both one drops, both somewhat filler however the Preordain is the filler you want, odds on it will make the final list while the Firedrinker might not. Then a lot comes down to what you think has a better chance of tabling.
Mausoleum Wanderer (Judges Familiar) 3
This looks good for the deck on paper but one point of damage is not enough threat given what else this card offers. The disruption is annoying but it is only going to be good if you have another actually relevant threat in play to protect. There are things that would stand to make Wanderer more playable in this deck but presently they either don't exist or are not quite enough for the archetype. Things that buff power would make one power evasive dorks much better in the deck but with generally few threats buff cards are weak. The other thing that could improve Wanderer is sufficient spirits such that it is getting a little bit more damage in on average.
Two CMC Threats
Stormchaser Mage 8
One of your best and most rounded two drops. This is hard to kill and hard to block. It scales very nicely with all your spells and can be used to take out planeswalkers very effectively. It has some surprise value which is always nice, you don't need to make it on curve for it to be very good yet it is a totally fine use of mana to lay on turn two. It is a cheap card of high power level but it has no fluff either, all that high power is concentrated in a dork that just punches well above its weight. It is much better than most of the one drops, more consistent, more powerful etc, even with the cost difference. Simply because of how many two drops there are that you can play compared to the viable one drops means that it is substantially less important to pick up than the one drops. Odds on if you can't table this relatively niche card you are in the wrong archetype for that draft! That or you have hate drafters or inexperienced players at the table I guess!
Looter il-Kor 8
An outstanding little card. This nibbles away the life totals and gets a bunch of valuable looting done at the same time. It is rare that this "kills" people but it effectively does a lot. When you get five damage out of the card as well as five loots spread out over five turns you are wildly far ahead. That really isn't that uncommon, when faced with a flipped Delver and this your removal spell is almost always going at the Delver. One of the most impressive things to me about Looter is that one of the main things that makes it good normally isn't really relevant in Izzet tempo. Often the ability to buff an unblockable body is what makes Looter so powerful all round but Izzet almost never plays ongoing buffs or equipment. It is already spread fairly thin across several card types it wants and is dangerously threat light as a result. You don't want to be playing things like equipment when you are light on things to put them on! So yeah, Looter is just ongoing card quality with some free damage. It is slow but it gets there much quicker and much more often than you might think. I think the unblockable creature aspect has been relevant for random Grenzo synergies before which is nice, it is also handy for that extra planeswalker pressure if you need and can forgo the loots. The value of Looter goes up when you have delve spells, Lavamancer and some of the recursion effects and cards.
Jace, Vryn's Prodigy 8.5
So this is pretty much another Looter il-Kor, you trade the free damage aspect for a different sort of threat. This is a looter for a bit, then it flips and is briefly a Snapcaster Mage until its finial form which is just a low value planeswalker that takes a while to get further value but none the less is a resilient threat and ongoing source of value and utility. Jace is great. Nothing new here. Jace super loves Grim Lavamancer and other things with delve and the like, more so than Looter il-Kor. This is because it can be more valuable to keep Jace looting for longer, five is a little to quick and easy in this deck, you are often at a stage where you still want more looting and don't need value yet. If you flip this which you are pretty likely to do if it isn't killed right away then it will be more value than il-Kor. Just one bonus spell of your choice and the residual walker is worth more than five free damage you might get out of a looter. Jace scales well with really good spells to recur, if you are all Lightning Bolts the recursion effects are better. This is likely irrelevant information, I can't imagine the mild difference in spell quality stopping you from ever picking this!
Young Pyromancer 7
Great card but awkward and needy. This guy gets violently out of hand if not faced off with removal or better tempo creatures. Most decks will have answers to this but if they don't it is a pretty quick and painful death. Against control you can make this and they have to kill it right away, if they don't you get to make an army for free while you sculpt your hand without extending at all until they find a wrath or die. Midrange decks can ignore it longer but the free value adds up, it is still a high priority kill target for them, the same with the aggressive decks. They might give less time for the value to made up but each free chump is worth that much more against aggro. There are numerous weaknesses of Young Pyromancer, the main one being he is a huge tempo setback. You have to invest two mana in a 1 health dork that can't really get involved in combat unless the board is empty or you are desperate. You are then incentivized to play spells rather than other cards which is often just wanking about with things like Ponder and while being great value isn't great tempo. Young Pyromancer is one of the cards most likely to turn you into the role of the control player. The second drawback of Pyromancer is that the prowess trigger is a more selective one that specifically needs instants or sorceries. This makes planeswalkers, Seal of Fire and a small selection of good cards a little less appealing. It also means you want to lean more on being spell heavy than creature heavy.
Thermo-Alchemist 7.5
This might seem underwhelming but it is an exceptional card in this list. This is pretty much a 3/3 vigilance unblockable creature. It doesn't deal damage when it blocks but it is none the less a great tempo card. You can even split up its damage to efficiently take out planeswalkers. This has the same support requirements as Young Pyromancer so is a good pairing for that. What makes it better is that it is not really a tempo concession making it when they have any creatures. The ability to block 2 power stuff and live is rare in Izzet tempo, the ability to do that and apply pressure is fantastic. This really helps out against matchups like white weenie where you typically are behind in tempo for the first couple of turns.
Kari Zev, Shiyship Raider 6
This is somewhat of a filler card. It is a nicely efficient threat with some mild evasion. It is the Goblin Guide of the two slot, one of the best card to plug a gap due to high power level but not something you massively want. Guide you do because there are so few one drops and they are so key, there are many more two drops and many more on theme and well suited two drops. This is one of the better filler cards but I think the 1R cost rather than a RR or UU cost is a big part of that.
Frostburn Wierd 6
This crops up in cube lists from time to time, mostly as a way to support devotion or blue aggression but it does work quite well in the Izzet tempo deck. The flexibility on the casting cost and ability make this super lovely to play, it is pretty much colourless in the deck giving you great freedom to curve out well. It may not have evasion but it is a royal pig to block. This kills a lot for free, trades with loads of stuff and can hit really hard if ignored. This is filler like Kari Zev but it is one of the best two drop filler threat on offer despite appearances.
Frost Walker 6
The big Phantasmal Bear. This is much more of a risk than Bear as getting it killed for free is a much bigger tempo loss for yourself. There are also lots of two drops that survive shocks, let alone pings or mere targetting! Frostwalker is nominally more risky than Phantasmal Bear and relatively even more so! There are some good payoffs for that extra risk. Like Bear, being blue can be nice. It can help you weight your early mana more accordingly with your late game mana needs. If you are playing Cryptic Command you need more blue sources and as such you will have more blue mana early and so you will want things to spend it on. Good support for Force of Will too not just for being blue but also for being a high variance card that typically should scale poorly as the game progresses. Frost Walker is one of your most lethal threats. If it lives and gets through then the game will not be lasting long! You are well setup to clear the path of things that efficiently block Walker as well so you can force it through easily early and often set up highly favourable trades with it in the mid game. About as on theme as Kari Zev but more desirable due to how it offers build flexibility.
Grenzo, Havoc Raiser 5
I nearly cut this guy from the cube as he is a bit win more. In RDW he is generally a 2/2, the times he is able to get you value you have already won. He could be any dork and the game would be yours. In Izzet tempo I have found him to be far more useful. Due to the high number of evasive dorks you have and the slower games Grenzo can put in a lot of work. He also scales nicely with the token generating things you might have. Both the goad and the Gonti/Edric effect are useful, the goad far more so than usual. Being able to control the combat to that degree and force through attacks, force trades or just straight up races is exactly what Izzet tempo thrives on. It wants to control the pace of the game, it wants value and it wants tempo and Grenzo is very well suited to do those things. The issue with the card is still very much that he is a RR 2/2. He is a poor tempo play on his own or even on curve most of the time. He is also awkward to play early being RR so can't often be a good backup play either.
Kiln Fiend 5
There are a lot of cards like this, things that trigger from instants and sorceries to gain a large attack buff. It has overlap with prowess but is narrower in a couple of ways. The more you play stuff like this the more your deck morphs into a different archetype all together that is much more like a combo one turn kill affair. Kiln Fiend is the only one that remains playable in the tempo archetype. Mostly this is because it only costs 1R but it is arguably the most powerful of that group anyway. While this hits all sorts of hard it is super easy to block and kill or just kill. More removal effects and even evasion effect start to look good when you have this card.
Thing in the Ice 5
Despite having great synergy with the deck Thing in the Ice is far more of a control card. You can flip this very quickly if you make it turn two but often you want to conserve certain spells and play out actual threats. As such this is a super poor aggressive play. It just sits there doing nothing for a long time, it it the Ancestral Visions of threats! Late game it is much much slower to flip and consequently a pretty limp top deck. This is a fine enough inclusion in most Izzet tempo lists but it isn't ideal. I think this is best as a sideboard tool as it is incredibly useful in a couple of matchups. Against any deck with heavier dorks in the early curve you struggle and a nice 0/4 goes a really long way to helping you win. If you can hold off a 3/3 with a 0/4 wall while beating down for a bit with evasion dorks then all is well. Trying to race said 3/3 with your lower power evasive dorks is not so good. The fact that that wall can wipe their board and become a 7/8 means they have to deal with it too. Midrange decks equally can't handle the two mana Evacuation plus 7/8. Those being slower decks themselves you are happy enough to play a slow and inconsistent card given how terrifying it is for them. They will have to remove it and a two drop with four toughness that needs hard removal or wins the game is a good card. Very good against most aggro and midrange decks but pretty awful against control and combo decks.
Rattlechains / Dimensional Infiltrator 5
These are pretty low impact compared to the other two drops threats on offer. The reason to play these kinds of cards is when you have more reactive and instant disruption. Being able to play a one drop threat and then sit back on two mana with either a counterspell, a removal spell or one of these flash fliers to bring in should they do nothing feels really good. Decks with more disruption tend to win slower which also works well with these cards as the evasion keeps them relevant throughout the game. Basically if you have a couple of two mana counterspell effects these are pretty good, if you don't have reason to keep up mana in their turn these are underwhelming.
Ankh of Mishra / Eidolon of the Great Revel 2
Warning! Do not pick and play these cards if you can help it. These are RDW cards and not really the kind of thing you are after. There are occasions these make for great board cards but overall they are not the kinds of thing your deck is trying to do. Eidolon especially works poorly with the card quality and draw stuff as well as your super low curve. You do far more to yourself with it than them and it isn't a significant body to go with this self harm! These are good against control decks but not so much so that they are worth including as they are such a liability against the quicker decks.
Kargan Dragonlord / Ash Zealot 4
These are the Satyr Firedrinker equivalents of the two slot. Often they are better than the one drops but they are so much less frequently needed that they have significantly lower value. The one slot often needs some patching up but the two slot is so chock full of juicy stuff you want to play you barely ever need to play the off theme or awkward filler. These are both fine cards, they will likely win you some games but they are not optimal inclusions in most situations (Dragonlord can be if you are heavy red and need mana sinks for some reason).
Three and higher CMC Threats
Snapcaster Mage 9.5
This obviously has a range from two mana to potentially ten I guess in this deck! I have put it at three as that is typically when it comes online in a significant way. Lightning Bolt, two drop, Snapcaster the Bolt again is so hard to recover from as a midrange or aggressive deck. You thought you were ahead with your Nacatl Fleecemance opener and you got wreaked. Snapcaster is everything you want in a card for this deck, it is a bit of a threat, it is some value, it is tempo and it is a spell most of the time too triggering all your synergies. Snapcaster Mage is a big reason why high value one drop instants/sorceries are so important. It is one of the only cards that you should consider picking over a good one drop or dual land.
Abbot of Keral Keep 7
Less reliable value and trickery than Snapcaster Mage but a much more dangerous threat. Most inline with Delver of Secrets in terms of support cards needed to improve its consistency. Assuring value with library manipulation is always nice. It is still totally fine to play blind assuming you have not yet made land that turn. Having a big two mana dork courtesy of lots of spells is a perk too. This is like Snapcaster in that it is a bit of most things but it is more weighted in the threat department, it is more proactive but far less consistent.
Chandra, Fire of Kaladesh 7
One of your best possible three drops. Awkwardly this one scales with red spells and so loads of things like Ponder don't help as much as they do with a lot of your other cards. Despite that you have enough cheap stuff, draw and selection that you can generally fuel Chandra enough without putting much effort into it. She can output a filthy amount of damage once online, most of which is unstopable. She is also able to flip somewhat easily thus enabling you do dodge whatever kind of death you fear she might encounter. A very threatening threat and a good chunk of utility as well.
True Name Nemesis 7
A mixed blessing. This is a resilient and unblockable dork. It is also one of very few tools you have that can effectively stop you being the subject of a beatdown. Against any sort of stompy or zoo deck a True Name is a real chore to attack into and not something they have much hope of removing. It is a bit like a Thing in the Ice against them except it can kill stuff when it is blocking, it harder to kill and effectively comes pre-flipped. Three might sounds a lot less than seven in terms of power, one is certainly much much less than eight! True-Name is still a better body though as the 1 toughness might as well be infinite (outside of trample) and the 3 power being evasive and there from the outset makes it far more useful. The two things holding True Name back are that it is pretty slow as threats go, not coming down till turn three at best and only then doing three per turn from the following turn. The second issue with True Name is that it is also just as vulnerable to mass removal as your other dorks, or at least the non-red mass removal effects. A big investment for you that will eat any mass removal on sight and thus take down anything else on your board with it. Casting this often feels like condemning yourself against control decks.
Goblin Rabblemaster 6
A filler three drop card for the most part. There are some cards you might play that have synergy with tokens, Stoke the Flames, Grenzo, I have even played an Opposition in Izzet tempo. Mostly however this is just a very good card. It has absurd damage output if unchecked, it has some immediate impact and it is hard to deal with in a way that fully or efficiently handles it. You are not desperate for three drops at all and so despite how good this is it is not a high priority card by any means.
Pia Nalaar 5
This is actually more the other Rabblemaster than Hanweir Garrison. The turn you make either they are a 2/2 and a 1/1, the only real difference is flying and haste. The Garrison, despite feeling like he looks more like the Rabblemaster is just a 2/3 when you make him and typically higher risk and lower value. Playable but very much filler and three mana filler is barely ever what you need or want. Anyway, Pia is pretty good overall. Versatility is something the deck thrives on and she offers a great deal of it. You don't often have much in the way of other artifacts and so her abilities last a little less long and have a little less scope than I have seen elsewhere but none the less she puts in decent work. One of few playable mana sinks in the deck too which is nice.
Vendilion Clique 6.5
Decent power, evasion, disruption and the sneaky flash. If you can reliably have double blue on turn three this is one of the best three drops going. It is even better, like the other flash threats, when you have countermagic. Much better in the control games than a True Name and often better in the midrange ones too. Cheap fat creatures is more of a problem for Izzet tempo than control decks are and so I have rated True Name above Clique but that is the only reason why, I much prefere the Clique in the deck. Clique is a more on theme and potent card, just not quite so specifically useful at countering your weak points.
Chandra's Phoenix 6
Quite the all rounder. This is evasive, it has some immediate impact, it is resilient and it has synergy with discard effects. Phoenix is incredibly easy to recur in Izzet tempo and can serve as a bit of a Sqee, Goblin Nabob to draw you lots of cards in concert with a looter. Being able to get value from a three drop without ever having to spend mana on it is a nice thing. Being able to extend into a Wrath and get some extra damage in is welcome too. The Phoenix is a very well suited card to the deck all round. The thing holding it back is simply that it is pretty fair compared to the other stuff the deck can play, especially at the 3 mana slot. Synergy wins out in the cheaper portions of the deck but as you get higher up the curve you are far more into the raw power.
Jace, the Mind Sculptor 8
Speaking of raw power we have this fella. Jace sets you up well while getting you value, he bounces their things and restores your tempo and he locks people out of the game by denying them relevant draws. They don't have much time to deal with a Jace before he has gained too much value to recover from. He has a little bit too much control over what is going on in basically every aspect of the game. Far more of a threat, as well as much more utility, than Dack Fayden and a mere mana more! This Jace is very much one of those cards that is powerful enough that you want it in your top end. I have had TMS and not played him but this was due to having a very very good list with lots of cheaper cards including Vryn's Prodigy. Usually I will happily play both in a deck.
Chandra, Torch of Defiance / Pyromancer 6ish
If you don't get a Mind Sculptor then this pair of walkers are acceptable replacements. I quite like a well rounded planeswalker in the four slot. These both do some direct damage, offer some card draw potential and both allow you to force through damage. Torch is better but not by as much as usual. I wouldn't want two four mana walkers in my list, let alone two four mana Chandras so that isn't an issue. Don't waste a pick on a second.
Thundermaw Hellkite 7.5
Such a heavy and quick threat for the mana. This dragon still gets it done in any deck. It is the premium five drop. It is the only five drop (that you pay five mana for) that I am ever happy to have in my deck, the rest are all filler and desperate problem solving tools. Even the various 4/4 haste flying things at 5 just don't put in the work Hellkite seems to do. I would play a Sarkhan, the not Awful or a Stormbreath Dragon but I wouldn't be happy about it.
Sulphuric Vortex 3.5
Warning! Much like Ankh and Eidolon these symmetrical effects are a bit too symmetrical for what is going on in Izzet. They don't do enough to merit the risk or cost. The lifegain prevention is nice but you are better off with a Skullcrack or a counterspell. Vortex does become good when you have a very cheap and aggressive deck with minimal blue nonsense going on!
Burn
Lightning Bolt 10
Super premium. This is the burn spell you want. With all the card quality and draw you have effectively nearly twice as many lightning Bolts as the RDW player when you have it in your deck. With the various recursion stuff on top of that your Bolt is worth even more. Great for prowess, great for killing high value targets incredibly efficiently. Just great. There are very few cards indeed I would consider picking over Bolt for this archetype. There is more suitable redundancy for burn than there is for the one drop threats but I don't think you can really pass on a Lightning Bolt and not expect someone else to take that signal and go into red. Don't pass it early and then go this route would be my advice. Only pass on it late when you have an option on something you really need more at that point such as a premium dual land or one drop threat.
Chain Lightning 9
Instant is nice for the trickery and prowess shenanigans but sorcery is fine. You are still mostly killing a thing pre combat and smacking so no real loss. The efficiency of 3 damage for one mana is the most important thing in Izzet tempo and so this is a pretty comfortable second best burn spell.
Fire / Ice 8
One of your premium spells. Great removal, wonderfully versatile and well known for just being all round good. Split damage burn is a little more valuable in Izzet tempo than most other lists. It combats the matchups in which it can struggle most effectively and works very well with your desire to be efficient and your ability to incrementally pump a number of your dorks. Not as important to pickup as the one drops and premium threats/burn. With this being best as a gold card and you hitting the Izzet dual lands really hard you have some expectation of tabling this.
Electroylse 6.5
Your deck has to be insane for you to pass up on this. Burn and card draw in one card is just too much exactly what you want. Just Shock and draw a card is decent, Pyrohelix plus the draw can be deeply unfair. This is clunky but you mostly suck it up and cope as it is so on theme. Try and wheel this if possible, if you don't get it back early you should perhaps reconsider your options s there is a good chance someone else is going to be thieving your dual lands.
Arc Trail 8
This keeps going up in my estimation. It is simply the best tempo play you can make in the early game in far too many situations. More over it is a total beating against you, having it is nice, not facing it is a mild perk.
Lava Dart 7
This is top five burn spells for the deck (excluding the gold ones). Having a free, instant prowess trigger you can use at any point is great. Dart triggers everything in the deck that has synergy, Chandra, Young Pryomancer, Thermo-Alchemist, all the prowess. It is good with looting too. Dart is hard to play around, gets loads of bonus value in the deck and has really impressed me. It is value, it is synergy, it is cheap and it is on theme, what more could you ask of a card?
Almost all other 1 and 2 mana burn found in cubes 6
Essentially these are the Shocks and Incinerates of the magic world and the many flavours they come in. Some with mild perks, some with more major ones and a sorcery penalty for them. I rate the one mana two damage spells slightly above the two mana three damage ones. This gap increases as I have Chain and Bolt and don't need the three damage as much. I also tend to prefer the instant options to the sorcery ones but obviously this is changes plenty with what you have and what you expect to see. Firebolt is one of the better one drop burn cards if you have the things that work best with it. Incendiary Flow might be the thing if you have passed nothing but Kitchen Finks all day! You likely want about 5 or 6 burn effects total. You obviously want the best but the step down from the best to the others that you will see in cubes (provided they are two or less mana) are fine. Get a range of burn, don't pick too much but also don't wind up with too little. That is much more important than getting the best burn.
Stoke the Flames 6ish
This can be nuts but it can also be clunky and hard to use. Even in the best decks for it (basically those with Rabblemaster and Young Pyromancer) where you can often cast it for little to nothing it still isn't an early game card. Turn three is likely the quickest it will come out. Stoke is great because it is instant, does any target and is super high damage per card. Taking out four or more toughness things is a total chore to do in Izzet tempo but does need doing now and again. Stoke is superb for this. An oddly good comparison is Grim Lavamancer, not for their role or effect but because they are both super powerful cards that work really well with many aspects of the deck. To get the most out of them however you have to pay a lot of attention to your build and play.
Fireblast 4.5
This is somewhat another one of those warning cards although annoying not always. You can absolutely play this in Izzet tempo but far more so than any other card you might play you have to do so with great caution. The best lists have so many dual lands that you won't reliably have two mountains. Perhaps more relevantly there are far fewer occasions you are happy to throw away two lands. If games are longer (than a RDW deck or other place Fireblast is exceptional in) then you will have Fireblast being dead in hand for longer on average and that isn't great. Four damage for no mana at instant speed to any target is incredibly great however! If your deck is looking more like a RDW list, if it is heavier red and has more threats and burn than usual then Fireblast will be great. More so than in conventional RDW due to the extra synergy of spells. You have to have the speed and the red to play Fireblast effectively, just one of those things and it will still be a little awkward. Playable still for its high power and your ability to negate its potential deadness with card quality.
Card Draw
Gitaxian Probe 8
One of your best pieces of filler and enablers. Always play this if you have it. The deck is all about quality so playing a 39 card deck is massively to your advantage. This turns on turn two Abbot and Snapcaster. It is a free trigger on all your stuff, a free card in the bin and free information. It is hard to rate it over a card that does physical things but still, one of the best cards in the deck. This is better than all the other sorcery card quality spells by a good way and probably Brainstorm too if you don't have Delver to flip.
Treasure Cruise 9
This is the card that pushed this archetype over the edge. In modern, vintage and cube all at once I think. In this kind of deck this is about as close to Ancestral Recall as you can get. You want to play tempo stuff early and so you don't miss out too much on the inability to play this in the first couple of turns, you have other more important stuff to do. As you run out of gas being able to refill for such a low cost enables you to keep up that tempo and apply stupid amounts of pressure. With all the cheap spells and looting it is very easy to power up the delve on Cruise. This is the first proper blue card (as in not Fire / Ice, Gitaxian Probe or Frostburn Weird) I would want to add to my RDW list. I gave this a 9 rather than a 9.5 as you can afford to miss out on it with there being a selection of alternatives to fill in for your card draw. This is by far the best on offer though.
Brainstorm 8.5
This ranges from the very best card quality effect by a long way to one of the weaker ones based on your list. Without any shuffle, scry or cards that want specific things on the top of your deck (Delver / Abbot) Brainstorm is fairly minimal effect. With those things it is the nuts and one of your most valuable pickups. Brainstorm is powerful and unlikely to table yet it is the kind of thing I would consider taking a Zurgo or Shivan Reef over. Brainstorm is a nice cards to have, you NEED the one drop threats and dual lands.
Dack Fayden 7.5
This guy is a real house. Looting is good, double looting is better... Not quite twice as good but close enough on average. Dack is the enabler of delve and Lavamancer. Although not really a threat any one with much experience of playing against him will deal with him asap (unless they can just kill you quicker) as they will know quite how tough it is to beat someone who gets two extra draws each turn! So despite not being a threat any sort of early Dack will be something they try and deal with and as such is a very good likeness of a threat. The ultimate on Dack is hard to use to much effect, you can steal some things with a bit of burn but otherwise it is fairly hard to target stuff. It seems scarier than it is and so a Dack closing in on his ultimate will suddenly become a bit more of a focus. The thing that pushes Dack quite a long way above and beyond is his -2. There are enough artifacts floating about that it is frequently pretty brutal. If you know of any specific brutal ones you often keep Deck a secret in hand so you can get that huge swing. It is pretty hard to lose if they invest in something potent like a Wurmcoil Engine and you just pinch it for 3 mana and get a planeswalker on the back of it! Even just pinching an equipment or vehicle with Dack is pretty hard for them to recover from. Dack is on theme for the deck and provides one of the only viable main deck ways to deal with artifacts in play.
Dig Through Time 7
Very good but not as good as Treasure Cruise in the deck. You have enough other quality and reasonable redundancy that raw numbers of cards is more what you want from your "big" spells. The double blue to play at max reduction rather than the single is also a pretty big deal. I always want one of these but I always want it to be Cruise. I have played both but I don't think it is good, you need all the looting effects for it to be a thing and you mostly end up throwing the first one away.
Peek / Opt / Quicken 6
The instant one mana draw things. I guess Whipsers of the Muse / Visions of Beyond and such should be here too. Generally these are just good to thin your deck, fill up your yard and trigger the prowess stuff at instant speed. These are filler cards but they are better than average filler of other types. You want the best threats and tempo removal and these effects, even the average ones, help you have them. Peek and Opt are generally the best, Quicken is rather narrower. The other U "draw a card" instants I think are generally all worse but not awful.
Ponder / Preordain /Serum Visions / Slight of Hand 6.5
These are your bread and butter card quality effects. Slight is actually worse than Opt/Peek in this deck but not by loads and mostly those two are weaker because they don't assist you in flipping Delver or hitting good with your Abbot effects. These are your best filler cards, they don't cost all that much mana, they fill up the yard, trigger your effects and ensure you have the best tools for the task at hand. You want all the best card from each group of cards but then you want these cards. They are better than filler threats. Every time you replace a premium card with a filler card of the same type your deck gets a chunk worse but ever time you replace one with one of these cards the deck doesn't suffer nearly as much. The very best decks might only play one or two of these but most weaker lists would play all that thy can get their hands on.
Jori En, Ruin Diver 5.5
Greatly improved with free spells so that you can trigger him when he comes in. Jori En is pretty easy to sustain, he draws somewhere in the 1.2 cards per turn region in this archetype which is pretty nice. The issue with Jori En is that he is a low tempo play and pretty vulnerable. If you are planning on getting gas out of this rather than a Treasure Cruise you may have that supply cut short with removal and not have enough to win the game. Occasionally Jori En gets to be a relevant body but in most of those you would be winning with any 2/3. Mostly he sits there just drawing you cards. This is great but Dack Fayden does it a lot better and safer.
Faithless Looting 6
This varies in value quite a lot based on the support you have. It is oddly good with other looting as it is good to loot away when you have another source of more efficient looting and it lets you push looting synergies further. It is a rare example of red card quality and so like the rare blue threats it can let you use your mana more effectively or simply allow you to build a better ratio of lands and coloured cards in your deck without loosing too much of the things you want. The big issue with Looting is that it is card disadvantage. If you have a lot of things that give you card advantage then it is great, if not it is quite painful.
Ancestral Visions 3
You want to make threats early not this. You likely won't have enough time to resolve this if you make it late. Much better in the slower more disruptive versions of the deck but still not one of the best ways to go about getting card advantage. I will play this if I need some raw card draw but I am not super pleased about it. No amount of wishing turns it into a Treasure Cruise when you peel it off the top.
Disruption
Vapor Snag 6.5
A very powerful card in the deck, so much so I would happily play Unsummon in the list. Probably not both, you can't stomach too much card disadvantage but the tempo gains from these cards are well worth it. These kinds of things really punish big cards. The ping is minor but does make the card better than the alternatives overall. You are still happy to bounce your own things if you need. I do like one bounce effect in my Izzet tempo lists and this is the best as it is the cheapest and most on theme.
Repulse 5
The Electrolyse of bounce! Tempo and card draw is an appealing package. It will do very well in most matchups but like Electrolyse you cannot play too much in the way of heavy cards. The more pricey cards you play that are not threats the more threats you have to squeeze in elsewhere. Likely taking up more total decks space so as to have sufficient total power to close a game. Repulse is mostly what you want but it is one thing you don't want as well.
Force of Will 7
Although exactly the sort of tempo disruption you want it is quite hard to play Force of Will. Having to keep a blue card in hand is tricky. Most decks are a little heavier on the red side of things. There are a lot more suitable filler cards from red than from blue, your blue stuff tends to be very powerful or very cheap. As such you don't have the supply of disposable stuff to reliably play your Force. If half your cards are blue then Force will be decent, too much less than that and I would probably avoid it.
Cryptic Command 7
So powerful and versatile that this is well worth playing if you expect to be able to cast it. Like the Force of Will this requires you to be heavier blue than the typical list. Ideally you want 75% of your lands able to produce blue, you can make do with a little less but not lots less than that. The versatility and tempo potential of this card make it well worth playing. Often it is tapping down their board to send in for critical damage. Sometimes it is counter the thing that was going to kill you and bounce the thing stopping you killing them. Due to the nature of the deck the Cryptic Command is typically incredibly game swinging. It solves a lot of issues and is just a very good very high powered card that is surprisingly on theme. The tap and bounce are far more useful and used in this archetype than in others. Neither being a threat nor a cheap card can be awkward, often you are using your few top end slots to play meaty finisher cards to make up for not having all the premium cheap threats.
Remand 6.5
One of the best disruptive cards as it is so on theme. It is a spell, it gains you tempo and it costs you no card advantage. If you get ahead and manage to hit a four drop with this it is super hard to recover. The one issue with Remand is that it is not proactive. It does nothing if you don't have mana up and you want to use your early mana to get control of the board. Good card but you can't have too much in the way of things needing you to have mana up, or at least you need to pair them with flash cards.
Unsubstantiate 6.5
A surprisingly good card in the deck. A good Remand isn't good because you drew the card, it is good for the tempo blowout and Unsubstantiate provides this. It is a remand when Remand is backbreaking and it is a more proactive Unsummon the rest of the time. Impressively versatile and on theme. You don't have loads of space for disruption nor can you afford loads of card disadvantage but Unsubstantiate does so much of what you want that it a good call.
Daze 7
The better your list gets the better Daze becomes. Nothing says I win like flipping a turn one Delver of Secrets with a Daze. Longer games and dodgy mana bases make Daze a somewhat weaker card. If you have four and five drops in your deck you are not quite so happy about using Daze on turns one or two. Potentially a zero mana disruption effect without card disadvantage which makes it potentially one of the best cards of offer. The issue is that there are significant potential ramifications to your ongoing tempo if played for free. It is also potentially effective card disadvantage if you don't use it in a wise and timely manner as it will become dead in the late game. You really want to be able to play a Daze but it isn't always wise.
Spell Pierce 7.5
One of the most effective counters for its cost and range. It hits most of the stuff you want counters for in this archetype, it does so well enough that they will really struggle to play around it. It is also cheap enough that it is a powerful tempo swing most of the time you play it. One of the best ways you have to cope with mass removal. Unlike basically all the other countermagic on offer the Pierce isn't a huge burden in some way. All the pitch cost counterspells are pretty painful on your other resources and all the other good counterspells require you to hold open too much mana. You can usually get out your threats with Pierce backup if you feel you need it and Pierce will usually get you decent value in any given matchup.
Mutagenic Growth 7
Free spells are where it is at! This is huge tempo, it has loads of synergy and it is terrifying to play against. With sufficient creatures and spell synergy this is something you probably want. It is such a low cost to include and play for you yet near impossible to consistently play around efficiently. As such you will frequently get loads of value from it where people just walk into it. Card quality lets you get away with a little bit more variance in your stuff. Combat tricks have always had a very good payoff when they come good and so the risk reward ratio is about as good as it gets in the decks with creature tempo and card filter stuff going on.
Arcane Denial 6.5
A cheap hard counter that is easy to cast. You don't want many counters and you want very few you have to pay much mana for. Unless you are all one drops and flash dorks I would avoid more than one or perhaps two two mana counters. Arcane Denial is one of the best but Mana Leak is plenty good too. Counterspell itself isn't the end of the world if you can have the double blue reasonably consistently. Negate is OK but I would greatly prefer Spell Peirce and both is a little limiting in this archetype. You don't need counter magic at all but the threat of it is nice. They make for fairly good and rounded disruption cards. The main thing to do is ensure you don't play too many. Cryptic Command doesn't really count towards this total, it is often just forcing through damage. For pure counterspell cards I think 0-3 is fine. If you are at the 2-3 end of the spectrum you want the majority to be one mana or have a pitch cost, failing that you need threats that cost one or have flash. With such little space for countermagic and a fairly plentiful supply of decent ones I think I have probably overrated the two mana ones a little. Izzet tempo is very much the kind of deck where the extra gas you got from Denial out values the gas they get from it.
Mana Leak 6
This is the deck where Mana Leak is closest to Counterspell in function. Due the the tempo constraints you put on the game three spare mana is not something you commonly face. As it is so reliably a hard counter it outperforms Counterspell simply by being 1U and not UU to play.
Izzet Charm 3
It might seem on theme and it is however it is a pretty low powered card and a pretty low tempo card. For the Izzet tempo deck that is a pile of problems. You pay too much for the versatility of this card and you don't need it. You are playing Lightining Bolt, Brainstorm, Spell Pierce, Faithless Looting and the like so that you don't need to roll those effects into one less potent package. Your good card quality makes Izzet Charm a waste of time.
A Third Colour
I am going to talk a little about the potential splashes you can make to an Izzet tempo deck. While I wind up going three colours in this kind of archetype in sealed deck a reasonable amount of time it is something I rarely do in draft. It is usually only the result of a confused or bad draft where I end up having to play three colours rather than actively wanting to. Your mana base is so important you cannot easily afford to compromise it which a third colour generally does. You can absolutely have a three colour mana base that is as good as a two colour one in cube but that is not the norm. You have to be very lucky indeed to even see all the premium on colour duals, you have to be even luckier to see them in packs where you don't have important picks for the straight Izzet version. Basically you don't have the picks spare to be able to consistently pick up all the important cards you want for your Izzet deck as well as the lands to support three colours. In sealed you get a bunch of extra off colour stuff so to speak and so putting it to use in a splash can be effectively free.
Rather than talk about specific cards I am just going to list the good and appropriate stuff for each of the three options and talk about what that colour does for the archetype.
Black Splashes
Thoughtseize
Inquisition of Kozilek
Dreadbore
Baleful Strix
Kolghan's Command
Dark Confidant
Tasigur, the Golden Fang
Gurmag Angler
Black gives you proactive hand disruption which is generally better than countermagic both for being proactive but also generally cheaper. It gives some nice efficient spot removal spells which combined with the discard stuff somewhat improve the utility and power of recursion effects like Snapcaster. Black also brings big fat threats with delve. Should you not have Cruise or Dig, or you just have all the best delve support stuff having access to the black delve dorks is an efficient use of your spare resources and adds another angle to the deck. Being able to drop out a fatty goes a really long way against aggressive and midrange strategies. Lastly black brings some nice card draw two drops. These are easy enough to setup such that they do draw cards or don't punish you too hard on life. They let you play the attrition game a bit better but they do typically make you more vulnerable to aggressive decks, particularly red ones. The addition of black often comes with a lot of extra pain, both from some of the premium cards and also from the extra lands you will need. The whole Grixis spread doesn't offer a lot in the way of lifegain, mostly it is heavy black and pretty unsuitable to include as part of a splash.
White Splashes
Path to Exile
Monastery Mentor
Mantis Rider
Lightning Helix
Soulfire Grandmaster
Seeker of the Way
Spell Queller
Reflector Mage
Mother of Runes
Selfless Spirit
Figure of Destiny
White is by far and away the slowest colour in terms of the additions it brings. A lot of the good stuff is three mana, a lot of it takes a while to impart their full value. By going white you are looking towards a more midrange play style. Your value, quality and power is higher but so is your overall CMC. White has some powerful and broad removal which is always nice. It has some prowess cards you can use to bolster synergies. It has some more evasion dorks to offer as well as some tools to protect your dorks. The white version is much better against midrange strategies and has a lot of game against aggro with some free lifegain options.
Green Splashes
Kird Ape
Atarka's Command
Flinthoof Boar
Experiment One
Birds of Paradise
Coiling Oracle
Shardless Agent
Lotus Cobra
Tarmogoyf
Green is a bit of an odd one. It is a viable splash but it tends to be a very small splash compared to black or white. Green offers a couple of interesting tools to boost your mana. These should be used with extreme caution, you can only play these if your fixing for green is incredibly good. If you cannot expect green in the early game stick to the other splash options in the colour. Mostly these are just cheap high value dorks. They can be used to pad out your curve but they are rarely something you want, just something you do when you need to.
Example Lists
Best Possible? - 0.8 average CMC!
27 Spells
Gitaxian Probe
Opt
Brainstorm
Ponder
Delver of Secrets
Cloudfin Raptor
Stromkirk Noble
Monastery Swiftspear
Goblin Guide
Zurgo Bellstriker
Lightning Bolt
Chain Lightning
Lava Dart
Pillar of Flame
Vapor Snag
Spell Pierce
Mutagenic Growth
Daze
Fire / Ice
Snapcaster Mage
Jace, Vryn's Prodigy
Looter il-Kor
Abbot of Keral Keep
Stormchaser Mage
Thermo-Alchemist
Young Pyromancer
Treasure Cruise
13 Lands
Island
Mountain
Scalding Tarn
Ux sac
Rx sac
Volcanic Island
Steam Vent
Spirebluff Canal
Shivan Reef
Cascade Bluffs
Sulphur Falls
Temple of Mystery
Wandering Fumarole
More Realistic
24 Spells
Phantasmal Bear
Satyr Firedrinker
Grim Lavamancer
Cloudfin Raptor
Vapor Snag
Zurgo Bellstriker
Firebolt
Pillar of Flame
Wild Slash
Opt
Ponder
Rakdos Cackler
Searing Spear
Incinerate
Stormchaser Mage
Kari Zev, Shyship Raider
Unsubstatiate
Looter il-Kor
Grenzo, Havoc Raiser
Serendib Efreet
Pia Nalaar
Electrolyze
Chandra, Torch of Defiance
Thundermaw Hellkite
16 Lands
Synergy Focused
24 Spells
Faithless Looting
Grim Lavamancer
Lava Dart
Firebolt
Gitaxian Probe
Mutagenic Growth
Stromkirk Noble
Cloudfin Raptor
Phantasmal Bear
Zurgo Bellstriker
Monastery Swiftspear
Slight of Hand
Jace, Vryn's Prodigy
Looter il-Kor
Stormchaser Mage
Young Pyromancer
Dack Fayden
Chandra's Phoenix
Chandra, Fire of Kaladesh
Jori En, Ruin Diver
Goblin Rabblemaster
Stoke the Flames
Thundermaw Hellkite
Dig Through Time
16 Lands
Red Focus
25 Spells
Faithless Looting
Goblin Guide
Chain Lightning
Monastery Swiftspear
Zurgo Bellstriker
Falkenrath Gorger
Gitaxian Probe
Pillar of Flame
Vapor Snag
Ponder
Goblin Guide
Lightning Bolt
Wild Slash
Abbot of Keral Keep
Searing Spear
Thermoalchemist
Fire / Ice
Stormchaser Mage
Snapcaster Mage
Arc Trail
Chandra, Fire of Kaladesh
Sulphuric Vortex
Goblin Rabblemaster
Stoke the Flames
Treasure Cruise
15 Lands
Blue Focus
24 Spells
Delver of Secrets
Phantasmal Bear
Cloudfin Raptor
Stormkirk Noble
Satyr Firedrinker
Burst Lightning
Opt
Peek
Serum Visions
Looter il-Kor
Frostwalker
Dimensional Infiltrator
Unsubstantiate
Young Pyromancer
Arcane Denial
Fire / Ice
Thing in the Ice
True Name Nemesis
Vendilion Clique
Electrolyze
Cryptic Command
Jace, the Mind Sculptor
Force of Will
Treasure Cruise
16 Lands
As you can see, there is a lot of overlap in these lists. More so than most of the examples I give in this series. Despite looking very similar these lists should play pretty differently as you will see and play a pretty high proportion of your cards relative to other archetypes. There are a lot of cards you can ram into these lists and I have discussed relatively few of the options. Other cards, even high powered ones are typically filler. The pool of cards from which you actively want to build your deck is fairly small compared to most of the tier one archetypes in cube however the pool of playable backup stuff is pretty big. A few slightly off theme of filler cards can be fine. Although the deck is very sensitive to change as you see so many cards each game the fact that it usually has card quality means it has some buffer. You can usually absorb the potential negative effects of a couple of cards. A stinker in RDW is actually worse than a stinker in Izzet tempo. Ideally you want some high power situational cards making use of this buffer such as a Mutagenic Growth and a Thundermaw Hellkite. One contextually situational and the other so for high mana cost but both capable of game winning swings. If your pool is weak or your draft went awkwardly you can use this buffer zone from the card quality to get away with some awkward filler. This in turn means in drafting if you expect things are not going well that you should pick safe role fillers over high power high variance cards more. Most blue and red things in most cubes are cards you can "get away" with in Izzet tempo. The less they cost the better, six drops are super uncomfortable. If a card says counter a spell, draw a card, bounce a thing, steal a thing, do some damage or is some kind of tempo board play and it is in a cube the chance are that the card will be OK.
One last post script comment. Lands are pretty much Volcanic, Steam Vents, Scalding Tarn (and other U/R sac lands once you have the duals to find with them), Shivan Reef, Spirebluff Canal, Cascade Bluffs, Wandering Fumarole, Sulfur Falls, City of Brass/Mana Confluence in that order. Temple of Epiphany and the many worse versions (life instead of scry or just plain nothing) are fine enough backup if you don't get good lands but the only land that comes in tapped that you ever want is the Fumarole. The card is rather underrated. It might not be a Celestial Colonnade but it does hit for four, is hard to block and hard to kill and as such is a very worthwhile string you can add to your bow. You are pretty unlikely to be activating it that often in the lists with 14 or less lands but in most Izzet tempo decks it is a lot of pretty painless extra value.