Sorry for this being out of chronological order, not really any big cube names from the final cards at least!
Noose Constrictor 3
Wild Mongrel comes back and has exchanged his chameleon hat for a reach stick instead. Wild Mongrel hasn't been a big deal in cube for over a decade with ever decreasing play that is entirely restricted to heavy discard themed decks. This is a little better than the Mongrel, reach just offers more to green than a colour shift does. All said, it is still a pretty limp card and will simply replace the Mongrel in the few synergy based decks that get made.
Stunning Regrowth 5
This reeks of combo potential. There are lots of good ways to fill up a yard with land and then there are lots of good things to do with having a lot of lands in play. I am sure you can one shot people with this fairly easily on about turn four with the right tools. Things like Squandered Resources and Bubbling Muck spring to mind. Alternatively things like Rude Awakening might be better ways to use a sudden pile of lands. This is far too narrow for a draft card but it strikes me as one of the most exciting combo cards that exists unbanned in the modern era of magic. I hope to build several different kinds of deck abusing this bad boy in many different ways. While it will never have that turn one game winning feel Fastbond often brings it will have that mid and late game Time Twister plus Fastbond feel of just getting loads of tempo and value in one shot. You could almost just loot and cycle lands till turn four and cast this and have ramped more than a lot of ramp focused decks. This is a very powerful card and although it is narrow it retains a wide application. It is only narrow in the sense you need to build around it rather heavily. This is the kind of card that gets Golgari Grave Troll banned again! At least it puts things in tapped, it highly restricts the immediate kill potential for the card and makes it ever so slightly more towards a Life from the Loam value style of card.
Working Together 2
More pleasant design. This card feels white and has a good use of the escalate mechanic. Beyond that I am not that sure what to make of this. It seems a bit all over the place to be of much use in the cube. Due to the escalate cost wanting dorks this isn't much of a tool for creature light decks. Any of the options for 3 mana is quite a chunk below par. This poses a further problem in that you therefore need to be in a position to use two of the effects. You have to be certain they will have a high powered creature or and enchantment while you have a sufficient board to buff. It is quite cute in that you can pump theirs guys so that it is big enough to kill it it wasn't before, still awful though! This card is far too below par to offset the mild utility it brings, the occasions it might come closer to par will be far too infrequent to have a significant impact on the cards overall rating. In addition to this it is incredibly narrow in the places you can actually consider playing it. Not the thing at all. Dromoka's Command is better in almost every sense.
Sigarda's Blessing 1
Cheap and interesting but so incredibly narrow it hurts. You can't play many of the buff types of cards as they themselves are situational, playing things to buff the buffs... In some mad Rabid Wombat style of deck (obviously not using that card though!) this could have a place but only due to overwhelming synergy, not because you should ever play something like this and expect it to be worth it.
Mausoleum Wanderer 5.5
Here we have the mono blue Judge's Familiar with two minor yet positively interacting perks. Perk one is a prowess for spirits, pretty minor with so few spirits kicking about in the cube but still, annoying to play against even if doing very little on average. Slightly more playable spitirts with flash at least! The second perk is a scaling on the effectiveness of the counter with the power of the Wanderer. Judge's Familiar only ever Disrupts a spell, this can Mana Leak it and more. All told it will be rather rare for the spirit trigger to occasion the increase in X, usually it will be equipment, buffs from creatures in play, planeswalkers and that sort of thing. This is one of blues best one drop tempo cards but it is either rather narrow or rather low impact. I like it a lot but unless blue gets loads of good flash spirits or loads of top quality aggressive dorks I fear this will not see enough play.
Heron's Grace Champion 1
Narrow as you like, exclusively playable in a green white humans deck and even then it isn't that much of a bomb for your 4 mana. It will give a big old swing but it isn't the game over card you want given all your effort of going tribal.
Courageous Outrider 1
A bit of a Ranger of Eos for humans. This is playable outside of a humans deck due to the general high human count in the cube and particularly white. It isn't great though, without near 100% chance of hitting this is bad. It has none of the tutor combo application of Mr Eos either which is his main use. While stats are nice the 2 toughness does not make up for the 1+ card less you get and the lack of options it brings. This is just a value card and as such it isn't powerful or tempo-ie enough to get a look in.
Imprisoned in the Moon 4
Blue gets its very own Song of the Dryads. What I have found with Song of Dryads and other comparable things like Beast Within and Chaos Warp is that there are very few decks that actually need or want them. Most of the more proactive decks don't need to go to such extreme lengths to deal with things and most of the reactive decks are just better off splashing another colour to help solve any specific problems it might have. Now, blue is more common a colour to do a mono deck that wants answers than green is. This makes it more playable than Song of the Dryads despite being a little weaker but I don't think it makes it quite playable enough for an A cube slot. One thing Song of the Dryads could do was ramp you by turning one of your own non-mana sources into a forest. This was rarely done due to being a two for one on top of a poor ass ramp spell in a colour full of good ramp. In blue however this might be more appealing as a ramp option. Especially if you have some bounce to get your thing back and reuse the Moon Prison. Generally I think I prefer the bounce solution to things you can't deal with in blue. Cards like Pongify and Curse of the Swine have never really worked out that well in cube for ways to keep things under control and I don't expect much difference from this.
Olivia's Dragoon 2
Putrid Imp has come back as a 2/2! For all your madness needs! Black's weak version of Noose Constrictor. This is super weak sauce but of course it is just about playable when you really want those discard outlets on command. To be honest, if I am desperate enough for my discard outlets to consider playing this I expect I am already playing the Putrid Imp, perhaps Zombie Infestation as well.
Crop Sigil 3
Great synergy with things like Divining Top and Courser of Kruphix but without some support then the card does little for card quality. It helps enable delirium but slowly compared to something like a Satyr Wayfinder. The recursion is nice, it allows a 2 for 1 but it is also fairly slow. There are certainly places this is a useful tool but it is low power and a little niche.
Make Mischief 1
This is a lot of mana to ping something and make a Goblin Arsonist. Not sure where a spell of these dimensions fits. Low power and awkward utility.
Power of the Moon 3
Hesitation returns in a non-symmetrical form. This seems pricey for something someone can easily plow through with a cheap spell. In the right situation it could be crippling but I think that will significantly be the minority of times. Counterspells at 3 mana need to out perform those for 2 mana and without the ability to chose the target I fear this falls short of the mark.
Abandon Reason 0.5
Heroic madness is a thing right? Moving on.
Primal Druid 2
Here we have another Viridian Emissary except this can't attack or pose any threat and therefore much harder to trigger. More health on a card like this is just a drawback really! Useful for emerge things but only playable as support.
Foul Emissary 2
A bit like a Fierce Empath, you trade certainty on a hit for the ability to hit any size dork. The emerge utility is super minor with this card. Emerge doesn't seem like a big thing for cube. The one thing I like a lot about this is that it clears the top of your deck and therefore has some nice synergy with things like Sylvan Library. Likely not powerful enough to sneak in any play.
Weaver of Lightning 1
While there is quite a lot of support for these kinds of card and this one has a decent body for what you are trying to do with it the damage output is simply too low. Half a Guttersnipe effect for the same cost does not make up for the bodywork improvements.
On this guy however the price is right! With a half reasonable body as well this guy only going one per thing is not an issue as he costs only 2. For the Guttersnipe style of deck this is top rate. It might even be viable in prowess or burn decks. It is almost a 1/3 unblockable that has nearly prowess for attack.
Shreds of Sanity 2.5
Powerful recursion tool in a deck with incredibly high instant and sorcery count. Potential use in some combo decks and even decks with a desire to discard things. As this is just 1 for 1 recursion it is not easily milked for further value. Far too inconsistent and slow to run in a prowess or burn themed deck.
Savage Alliance 1
This seems a bit too situational, a bit too expensive and a little at odds with what you will be trying to do with most decks. I am a fan of the mechanic still but this card isn't there.
Prophetic Ravings 4
Very interesting card. With being both cheap and giving haste it will be rare to get blown out while trying to use this which is the reason most aura cards fail to see play. This card has some interesting synergies and a couple of applications. One is just hasting up something, not worth a whole card but when it is the thing it is powerful. The other use is getting some looting on the go. You have to get at least 2 loots out of the card for it to be worth playing over a Neonate which will generally mean having it and the dork it is on survive a turn however with cards like Thermo-Alchemist you can have some fun. I think you will still need quite a lot of reason to play this card, I cannot see a RDW just throwing one in. Not that many decks which are keen to loot have a high enough creature count for this so I suspect it will not be getting much love.
Otherworldly Outburst 1
Lots of stuff for 1 mana but too fiddly and slow to setup to ultimately be worth the mana and card.
Furyblade Vampire 3
This is quite a beating if you discard every turn comfortably. For a madness tribal vampires deck this is going to be one of the best cards, it is actually an ongoing aggressive discard outlet that costs nothing to use and is cheap to get down without being well below the power curve. Too expensive to fuel without a discard theme however and so too narrow for most drafting cubes.
Distemper of the Blood 2
Double narrow for being a combat trick and a madness card but pretty powerful.
Impetuous Devils 3
Ball Lightning gets provoke! Interesting card but far too pricey for a one health card. This will get pinged or blocked by first strike dorks too much to be a good spell. Sometimes it will be Searing Blaze, sometimes it will be a very efficient burn spell on a dork or at face but other times it will clog up your hand wishing it was a Lighting Strike.
Borrowed Hostility 2.5
Another viable heroic card! Decent utility but expensive if you want to get max value from it.
Succumb to Temptation 4
Instant speed 3 mana draw 2 is good. Paying 2 life for it hurts especially for the kinds of deck that want this sort of tool. Cool card none the less. Good to finally have this option even if it isn't in blue.
Graf Harvest 2
Super narrow but probably good enough in the most aggressive of zombie decks.
Scour the Laboratory 5.5
Simple but effective. Fact or Fiction has this cards number but this is the closest a card has come to being another solid instant card draw card. For six this is quite uncomfortable but for four it is lovely. While I don't expect you will often have delirium on turn four you should have it by turn six which is when you can realistically expect to play a Fact or Fiction and not die. There are some decks which really don't want to put any cards in the bin, few these days but still. Scour the Lab would be an ideal FoF replacement in such decks. Probably this won't last that long in the cube as Fact or Fiction itself is so infrequently played due to the importance of tempo and the value permanents yield these days.
Geist of the Archives 1
Too slow and too light of an effect for a 3 mana card. If Sigiled Starfish isn't getting play then this certainly isn't.
Nebelgast Heral 1
I guess this subpar Perstermite may see some tribal spirits play if that is ever a thing. Turns your Mausoleum Wanderer into more of a Spell Pierce!
A bit of evasion, reasonable defensive stats and a tempo effect are all quite nice but rather low impact. Things like Send to Sleep see little play and do the kind of thing this does generally better. This is just not doing enough reliably enough to be a worthwhile control card. As a more tempo based card it is fine filler if you have some other things that work with it. Creature type presently lets the down a lot and means it likely wont see any play until spritis becomes a big name...
Double Flicker! I like to get my flicker effects on other things and not run these kind of situational card. Though the flicker theme is strong in the cube this is not a card I would have any interest in using in such decks. It isn't even that cheap nor does it protect against wraths.
Ironclad Slayer 3
Decent stats for a card with such a direct two for one. Being quite limited on targets however the card is very narrow. Even when in the optimal sort of deck the card will only perform that well in the latter parts of the game.
Vexing Scuttler 2
This seems one of the weakest emerge cards. Basically just a fatter Scrivener. It isn't great value and it is a little counter synergic wanting both creatures and spells. If emerge does a thing then you might use this but even then that is only a might. The same really applies to all of these latest emerge cards. They just don't look in anyway better than similar cards without emerge. Abundant Maw, It of the Horrid Swarm and Mockery of Nature all seem super weak even when you actively want a sac outlet. Drownyard Behemoth is a bit trickier but just isn't worth it at all for what is just a reasonably big do nothing dork.
Conduit of Storms 3
I love me a card that offers mana and this one also offers to be a threat early and again late, is himself a mana sink and is generally just really cool. Sadly even an extra toughness does not make a Grey Ogre good and that is essentially what this is in terms of offensive potency. Ramp is nice but this is a little late in the day to be that exciting. While I want aggressive cards that also ramp this is not the package they need to come in, even for a red card.
Extricator of Sin 6
The last card getting a review from the set and a fairly interesting one at that. So the starting point for this card is a 0/3 and a 3/2 should you sac a thing. This is more stats than a Blade Splicer but less actual immediate board control with no first strike. It also assumes you sac a thing which really is what will define this card. Cards like Flagstones of Trokair, Doomed Traveler and I am sure many others than presently are not in my drafting cube would make this card really quite exceptional. In a standard good stuff deck with little synergy having to sac something is going to hurt a lot of the time. It makes this a card you want to play later, when you are done casting things and either have useless one drops or excess lands. That isn't an ideal start for a card but there is a lot more to this tale. Because it is generically good tempo and value assuming you sac something of no consequence it is playable in a wide array of decks from aggro through midrange all the way upto control. Because you can sac stuff it even has application in some combo style decks, notably with Academy Rector.
Now if it was just that, the 0/3 and the 3/2 with the sac effect then the card would be too low powered for how narrow it is. Perhaps a tiny bit of play in some weird decks but nothing regular or impressive. The delirium transform effect is very powerful indeed though and should see this getting some love. This card will be a complete beating in limited if delirium is easy to achieve. In cube, draft or otherwise, delirium is a whole lot easier and quicker to come about than in Innistrad drafts and so this is potentially just a good card that you can play with fairly little regard for synergies. Being able to sac a thing makes delirium easier to achieve of course and a 3/5 vigilance that turns excess rubbish into 3/2s with vigilance as well is all sorts of good value for 3 mana. It will attack and block and basically need to be the first thing removal hits else all will get out of control. It is not the quickest or the most powerful but it is a card that can win a game by itself and it is a card that is fine on curve and fine late game. These things add upto a card that should be pretty playable.