Slaughter Pact 1.5
This is mostly in the cube for a bit of variation on other removal being free to play. Sickening Shoal and Contagion have all had A cube time as other free removals spell in back. Each has its ups and downs but they are not powerful enough cards to all warrant inclusion. The pact cannot be used until turn three most of the time but doesn't cost you card advantage or require you to have enough black cards to readily pitch. This makes pact more playable in control and multi coloured decks. I am happy enough with the card having a slot but it sees relatively little play as Doomblade is just cheaper and more consistent. Pact rarely gains you tempo, it will rather keep you ahead if you already have an advantage being most effective to kill monsters in response to equips when your opponents presumes they are safe. If you are already behind on the board this may bring you closer for a very short time but due to losing three mana the following turn they will likely pull ahead again.
This card really surprised me in how much play it has seen since its quite recent introduction. On the face of it it looks like a poor shock that you can't aim at the dome. One mana instant removal is great, the early turns are important and in them mana is tight and creatures are usually small. Disfigure has seen play in almost every kind of black deck that has neither red or white in it. While a less versatile card than shock disfigure is more versatile as a removal spell due to use in combat. Blacks removal tends to be quite situational and disfigure turns out to be one of the least situational being able to target any monster, if not always killing it alone. Disfigure also enhances the power of blacks edict effects better than any other spot removal black has to offer. Most of the monsters in the cube are cheap utility monsters or card advantage speed bumps to which disfigure is an efficient answer most of the time. If you have overlooked this card for your cube as under powered I recommend giving it a try.
A wonderfully designed card and a theme I would like to see further explored. This is blacks best pure agro one drop creature, or will be until gravecrawler is released, upon which this card will only make the crawler better. This has nice synergy with Kor Skyfisher although anti synergy with AEther Vial. Black is presently very thin on cheap aggressive monsters although most of the ones it does have are of good quality. Rather than getting relegated as new powerful black monsters are printed I think cards like this will see more play over the next several years as black agro decks get better. Obviously this card has synergy with zombies, more subtle synergies include Nyvineraals disk and Smokestack, both of which find homes in black decks more than other colours. The sarcomancy is also weaker against blue decks due to bounce effects of theirs. This however tends not to be an issue based on his low low cost.
Cabal Therapy 3.0
This is one of my all time favourite spells so my rating could be a little biased. Cube being a singleton format makes this card worse, as do certain draft formats done in cube. Nothing however is more satisfying than working out, from the cards they might be playing, which wreaks you the most and then hitting it blind. Therapy can be a real skill tester and even when you know what is in their hand from a previous discard spell is still generally harder to use as it can hit the most cards. The more duress style cards you play the better therapy gets but it does rather call for a deck to want to abuse all aspects of the card for it to really shine. Oath decks often play it in the hope to mill it so that they can instantly sac an Academy Rector. Rock type decks make use of it to get viridian emissary or genesis (or a target for him to remake like an eternal witness) in the bin. Reanimator decks sometime apply it to themselves to get their targets in the bin directly from the hand. Bloodghast, and soon gravecrawler too, make the therapy easier to use to its full capacity without harming your own tempo or card advantage.
Vampiric Tutor 3.0
A rating of three seems really unfair as this card would have been a comfortable 4.0 when I first started playing cube. As combo decks have become less and less viable due to the speed of aggressive decks and control decks have shied away from card disadvantage as the aggressive monsters get more inbuilt card advantage of their own the tutor has gradually fallen from grace. This used to be a top three pick in black and a really strong signal, now it comes round late or gets left in the sideboard. Tutor effects are more powerful in singleton formats and one mana instants are as close to optimal as a coloured spell can be. Tutor can fit in almost any deck and does allow decks to be built very differently. Sadly I cannot foresee a return to the dominance of combo in the cube and so the tutor will remain infrequently called upon. Life is a precious resource for black decks and two is often worth more than one card. The vampiric tutor sees more play in decks splashing black than in mono black decks for this reason.
This card is really bad against red deck wins. Black is also one of the only colours that really cares about life as it has so many ways to use it as a resource to draw cards. These two occasional downsides make this a very well balanced discard spell with it being the best at that function (unless you are perfect with cabal therapy I guess..). Each of the one mana look at their hand and have them discard some card spells are never strictly better or worse than the others and are very even overall. The choice to play which and how many depends entirely on you deck and match ups. Generally they improve one another as you play more, particularly cabal therapy, however they become quite bad top decks as the game progresses. The targetted discard has wide application in all kinds of deck and with most decks not overly concerned for their life totals this is probably the most played of the lot.
Inquisition of Kozilek 3.8
This card is the one biting at the heals of thoughtseize only allowing me to say it was probably the most played of the lot. My cube is a very low mana cost meaning that Inquisition hits at least 80% of the cards in the cube. It can hit creatures but is no weaker against decks with no creatures making this the safest discard spell to play when you have no real idea on your match-ups. Thoughtseize is inherently weaker against agro too making Inquisition the safest option overall and the best outright against aggressive decks. Its slightly random nature can be irritating, when you need to hit a counterspell and they haves force of will and cryptic command for example. This does exactly what you want a discard spell to do early and that is when you want to cast them. When offered a selection of targeting discard spells to play on turn one this is the best. It may not shine so heavily in other cubes with much higher mana costs but then I would strongly advocate against such cube builds as they make for a dull linear and more random experience.
Dark Ritual 3.6 (4.0 in a powered cube)
This sort of effect is much better when you have redundancy in it and can rely on seeing it to an extent. The other black spells like this are pretty weak but ritual did enjoy a strong relationship with black lotus. Now it has to settle for lake of the dead and is less abused as a result. Black is a slow colour but able to refill their hand quite easily making ritual a perfect card for it. Red cannot really afford the card disadvantage and therefore the red rituals are far far weaker. Swamp, Dark Ritual, Necropotence is a classic play and remains very strong in cube. Ritual also fuels a Yawgmoth's Will turn very effectively. Any deck that needs to spend a lot of mana fast or can afford/recover card disadvantage will consider ritual if reasonably black. Cards and mana are the best two things in magic and this is one of those things. While no ancestral recall it is much closer to that end of the spectrum than the healing salve end.
Probably the narrowest of the targetted discard spells in the cube. Duress makes up for this with reliability and consistency at what it does, mostly guaranteeing to take a counterspell from their hand if they have one. Hitting planeswalkers and equipment has helped to keep this card playable against agro even if still the weakest discard spell choice for the match-up overall. Duress is most happy in combo decks but can find a home in any black deck you care to mention. Whether Duress is included in the discard package for control or aggressive decks will entirely depend on what the deck is weak against and what match-ups are anticipated. Blackmail, Raven's Crime and Despise have all been tried in the A cube and were found to be weaker and narrower than Duress and overkill on the quantity. No 40 card deck wants to be playing 6 or more one mana discard spells, 4 is hard to support in most decks. I am sure we will see more cards of this nature, the next good one could join the others or replace duress depending on what it does but I cannot envisage a card that would replace any of the other current targetted discard.
Bad Moon 1.0
I deeply dislike this card in the cube as it only fits in one deck - mono black agro. This makes it very narrow and, unlike Crusade it has no redundancy worth consideration, nor is mono black agro as variable or powerful as white weenie decks. Sadly I think black needs this card at present. It has far far less options of powerful creatures at its disposal than pretty much every other colour and has less good ways to improve those creatures such as Rancor, Stoneforge Mystic etc. to call on. Black does have a reasonable number of generic two power one mana dorks which do beg for a card like this. 3/3 is a significant jump on a 2/2 in the cube, as so many guys are 2/2 and smaller combat starts to heavily end in your favour. I think black needs three or four creatures of high power costing one to three mana to be printed before this card can be retired, even then, unless black has some more acceptable ways to boost their guys the narrow moon will continue to be desired on occasion.
Demonic Tutor 4.0
The benchmark for tutor effects, it has no drawback, no stipulations and is a bargain at two mana. The only decks where this is not an auto include are the very aggressive ones full of redundancy as the two mana is a setback to them. Even then as they are black they often run Necropotence for which Tutor offers more affordable redundancy than Yawgmoth's Bargain does. Tutor also allows you to be a little riskier on land count and run less redundancy in your specific answer cards freeing up slots for action cards. Tutor is at its best in combo decks but will see play in almost anything black and is one of the few black only cards that gets splashed into decks. Frequently played in decks with good synergy cards like the Recurring Nightmare rock decks as it helps to set up your engine better and smooth out the deck even if the deck is not reliant on the combo. With Vampiric Tutor you really need to have essential cards to go and find to offset the card disadvantage and life loss. Demonic can be thrown into decks without a need of tutor effects as the most damage it can cause you is the loss of two mana.
Most cards in the cube are of a comparable power level when played in the cube as they are outside of it in the various constructed formats. A few cards really shine in the cube that have never seen much success outside of it. Some cards such as Accumulated Knowledge simply don't work properly in the cube and see no play as a result. Very few cards are in the cube but are much less exciting than they have been in other constructed formats. With the low rating and all that preamble I sure you can guess that Bitterblossom is one of those cards. Black has loads of uses for life and while the cost of this card is certainly good it is still a very slow card. Generally black will see a more immediate return on their investment of life than Blossom can offer making it too painful a choice. In the agro decks it is the slow nature of the spell and in more control decks it is the life loss that ultimately sidelines the card. It has pleasant synergy in some regards with sacrifice effects and Bad Moon and it does see a decent amount of play. It is only really good as an different threat to pose against control decks on top of walkers, guys and man lands. One of the best homes for this card is essentailly a white weenie deck that splashes black for a few juicy cards such as Vindicate and Dark Confidant. I think the best synergy for this card is with Cataclysm, particularly as white is so indifferent to the life loss.
Rather good but rather bland as with many of the earliest overpowered spells. Sinkhole is at its best on turn two while on the play. Later on in the game it is often fairly dead unless they happen to have a particularly annoying utility land. In this respect it is quite like the one mana targetted discard spells, very powerful early but getting progressively worse as the game progresses to the point of basically being a dead draw. Because of the difficulty in casting it when optimal it rarely sees play outside of mono black decks. Despite this Sinkhole has two distinct archetypes as homes which is enough for a card of this power. These homes are Pox style decks and very fast aggressive decks however it has seen play in BW, BG and BR decks. Classic land destruction decks trying to cast things like stone rain are way too slow to be viable in the cube leaving only global effects with enough power. Sinkhole is the only spell that must target a single land in the cube for this reason which makes it harder to usefully include in decks. Despite all this, particularly without the Moxen and other power, Sinkhole is a card that will outright win you at least one game per cube, often more. Whenever you get it early against a deck which slightly hiccoughs for land in colour or quantity there is a high chance that the single land kill will put them too far behind to ever recover. Free wins are nice but a little dull and so I tend to only play this when it fits with my decks strategy however that is almost certainly wrong, my advice is to 100% of the time play Sinkhole if you have no colour mana concerns at all.
Hymn to Tourach 3.6
There are some reasonable comparisons between this and Sinkhole. They are both well undercosted, they are both fairly restricted to heavy black decks and they both shine earlier in the game with the possibility of being dead later on. I am not a huge fan of random effects and this is one of the more brutal. Cast on turn two there is a good chance that hitting one or two of a few key cards will be game over. More often than not it is losing the land that spells disaster. At its best this card is far more powerful than double Coercion (mana cost aside) and at its worst it is just two Raven's Crimes. A swing of power that extreme over which there is no control on a card still very much good enough for the cube does mean the card is pretty tedious to play with and against. If a player could exclude any number of lands they chose from the random discard then the card would be much more balanced. As it stands it will often just get chucked into a deck that can support it just for the few free wins you will get from it gibbing your opponents, much like Stripmine and Sinkhole would do.
After Balance this is about the most powerful effect in the game for less than four mana. The card is a mainstay in all black based pox style decks. Pox itself is rarely played with this, Deathcloud, Braids and Smokestack all generally being easier to abuse. Smallpox has fantastic synergy with black in general as it often wants discard outlets and sacrifice mechanisms. Assuming your deck is built to cope with the symmetrical nature of this card it becomes incredibly powerful and versatile. Basically it is a Chainer's Edict or a Sinkhole or a Raven's Crime or even just a ping to the dome. Not only can you use the card for one of these effects to gain advantage but when correctly engineered you will be able to take advantage from more than just one aspect of the card. It is greatly satisfying to cast this on turn two while on the play when your opponent has made one land and one creature on their turn so as to completely de-permanent them.
Doom Blade 3.5
This little spell has worked its way up to the slot of best black removal spell. I deeply dislike the inability of the card to hit black monsters although it is rarely relevant. I also hate the way white has two removal spells that tower above this in power level. Such is life and we must make do with the weaker options. While black creature removal has not increased all that much in power since the dawn of magic the immense increase in power level of creatures in that time has made that removal much more useful and playable. It is rare I will build any black based deck and not at least consider the Doom Blade, most of the time it will make the final list too. Most decks play creatures and most of them are pretty good so you will be happy to be drawing this even though so many monsters will net some advantage for the caster without ever getting to combat. When your not white and you want to be getting stuff dead without much fuss this this the card.
Go for the Throat 2.5
Most of the time this is just Doom Blade. When Doom Blade is good it is Terminate but easier to cast, when it is bad it is usually completely dead. Go for the Throat can still wind up dead against artifact decks as a Doom Blade can against black decks however the are way more decks that have the odd artifact than their are that have the odd black creature. This means most of the time Go for the Throat won't hit every guy in their deck unlike Doom Blade which most of the time will. That extra little bit of inconsistency makes Go for the Throat significantly weaker than Doom Blade and used only to give redundancy to a deck already playing it or when you know you are facing a a high percentage of black decks. I can't get too excited about cards like this, they are required in many decks and get the job done most of the time. Cheap instant targetted removal is always a useful thing to have as an option and almost all decks play guys these days. Tragically this is probably blacks second best targetted kill spell that is not concerned about creature size or cost. It just seems so unfair when red has mutti purpose removal while black gets more expensive situational removal. Let alone going into how unfair it is compared to whites removal.
Chainer's Edict 1.8
I have always flip-flopped between the card advantage from Chainer's Edict and the instant speed of Diabolic Edict. The cube does not have room for both as they are not often played. I suspect I should probably solve this age old problem of mine and go for a somewhat different card and play Innocent Blood in that slot. Black has a number of ways to force creatures to be sacrificed and all are sorcery speed except the Diabolic Edict which is a reasonable argument for it over this. Either way these one for one (at a reasonable cost) enforced sacrifice spells are not all that good in the cube. Most decks with creatures either run many utility creatures that will have already provided most of their effect or lots of cheap gribbly beaters. While edicts are the only single removal spells capable of dealing with many of the creatures in the cube they are hard to engineer a game state where they can be used to do that. Most of the time randomly killing their worst monster is not worth the card or the mana. Best played against reanimator combos and control decks or in decks using mass removal.
Smother hits most guys in the cube and is never dead against certain colours or archetypes like Doom Blade and Go for the Throat are. The problem with it, a little like with the edicts is that it often isn't hitting the best monster. The card this is actually most comparable to in the cube is Disfigure. Neither can kill the bigger more expensive monsters and tend to fill the role of cheap early removal to retain tempo. In this Disfigure tends to win out for being cheaper and of some use against monsters it cannot kill even though Smother will kill more of the monsters in the field. If you compare Smother to one of the Edicts it comes up a little less favourably as it does not have the capability to deal with hex proof, shroud or indestructible monsters despite being better at killing the weaker monsters on the board when lots of things are in play. All in all I don't think that Smother really has any homes left as the other removal spells all do things a bit better. It is all pretty marginal though.
I have been very disappointed in this card. Black doesn't want to pay life much and has cheaper better removal at its disposal, as such this never sees play in black decks. Thus far it hasn't seen any real play outside of black either. Commiting to paying 4 life for a removal spell is a tall order for any kind of deck. Red has much better options of its own and would turn to artifact damage sources before Dismember should it fear protection from red dorks. White has better cheaper removal than black already. Blue has no life gain, decent bounce, counter magic, evasion monsters, reasonable chumpy blockers, control magic effects and even Opposition to deal with guys all of which means it has no particular recourse to use Dismember. Green is the only colour that might find Dismember useful with decent life gain and a total lack of generic cheap creature removal. Thus far I have yet to see a green deck impress me using this card and we be removing it to the B cube or lower unless it does so very soon. Green has the mana to use cards like Duplicant and Triskellion as removal and always has Beast Within if desperate. Green also has pleanty of good dorks that can go a long way to negating a need for removal. The final nail in the coffin of Dismember, other than having no homes, is that it fails to kill the most fearsome of threats, Titans, Wurmcoil, Consecrated Sphinx etc. They should have made it a tribal Demon card and had done with it...
Another of my favourite magic cards complete with great art, great power and pleasant nostalgia (I started playing in Ice Age and played Necro (badly) in my first tournament). Necro is quite a hard card to fit into a deck but is well worth it when you do. As far as raw card drawing power Necro is basically the best you can do for the mana. The drawbacks of the card are numerous so as to slightly balance the card. Skipping the draw step is only relevant after the life loss takes its toll as it can lock you out of the game. The life loss in general is not a real concern unless against aggressive red decks. You start with 20 and only need one. A potential to get 19 cards for 3 mana puts Ancestral Recall to shame. You tend to have won well before you have sent 19 life into cards. The main thing to consider is when it is safe to make a Necro when under pressure and how many cards you are able to get without putting yourself on an unrecoverable clock. Access to life gain is useful in decks with Necro but does not need to be that overdone, a Zuran Orb and a Vampire Nighthawk would be more than sufficient for most games. Ivory Tower is a great card in this role too but has few other homes without Necro and so is no longer in the A cube. The Removing cards from the game stops Necro being a good way to fill up your graveyard with things you want to reanimate or otherwise. Beyond that the exile aspect of the card just denies certain combos utilising it rather than making it worse in decks that use it as it is. The most significant drawback as far as I am concerned is how it gives all your draws summoning sickness making your response time to things somewhat slower. While a little annoying to use with card arriving at the end of turn it makes the card much more interesting and complicated to properly use. Having access to cards that can remove Necro such as Nevinyrral's Disk with it is nice so you can recommence drawing when your life total is getting low or just after a complete hand refill in the mid to late game. Typically played in mono black decks due to the cost but more deadly in decks of more colour if able to cast. Best in decks with lots of cheap cards so as to be able to play more and thus draw more cards with the Necro quickly without exceeding seven cards in hand.
Recurring Nightmare 4.2
The way in which my cube is evolving is making the Nightmare better and better. Most creatures have either a comes into play effect or a when this dies effect. The ratio of creatures to spells is ever increasing as is their power. Recurring Nightmare is a cornerstone card in many different decks, typically having best synergy with green and white. Less commonly found in pure agro decks it can still find a home in more techy agro builds, primarily it is used in slower decks or combo decks such as reanimator. It offers all the usual useful things such as a good sacrifice outlet and the ability to reuse effects you have little redundancy for due to the singleton format. Although it doesn't guarantee card advantage the kinds of creatures that are played with it ensure that you will either be getting card advantage or vast mana advantage. The card this is most comparable to is Birthing Pod however while they offer a similar effect the process is somewhat different and so the cards never compete for a slot. Often they are complimentary to one another and offer redundancy to abuse your card advantage monsters. Genesis is another card that fulfils some of the same roles. Genesis is robust against counterspells and does not require the sacrifice of creatures to use but is worse in all other ways. Often you want to be sacrificing monsters anyway. Nightmare is powerful enough that you build your deck noticeably around it and so unlike most other cards that require specific aspects of your deck to be tailored towards it the rating does not suffer. Other cards of this power include Skullclamp, Tinker and Goblin Welder. As the requirements to abuse Nightmare are abundant in the cube, much more so than for Goblin Welder or Tinker, it is easier to include in decks and to draft.
Liliana of the Veil 4.0
This is the best new planeswalker to grace the cube since Jace, the Mind Sculptor, blacks best walker and the best three mana walker too. Liliana has good synergy with black being able to make good use of the discard outlet effectively in a variety of different styles. Liliana is also capable of protecting herself with the edict effect and at only three mana she can come down early, clear the board and then steadily grow to win the game. Planeswalkers that have no means of protecting themselves are generally too weak for the cube as they are generally quite expensive sorceries. Koth of the Hammer gets away with it for being super aggressive (and is quite weak anyway) and Jace Beleren is also playable due to being cheap and having a +2 loyalty effect allowing him to take a few hits. A walker at three mana with self protection capabilities and useful growing abilities is always going to see play and Liliana does not disappoint. She is great against control and decent against agro and combo, she also fits into most of those types of deck too. Her ultimate is one of the least certain ones of all the walkers to win the game although it is still pretty likely if you do manage to get it off. On top of this it is one of the cheaper ultimates at only 6 loyalty. All in all Liliana is a very well rounded cost effective planewalker that sees play in most heavy black decks.
Yawgmoth's Will 4.0 (4.6 in a powered cube)
In the early days of cube Will was honorary power and was picked alongside cards like Timetwister and Moxen. In the late game there are few top decks more likely to straight up win you the game than Will. When compared to the gain in cards from things like Timetwister and Wheel of Fortune you not only have prior knowledge of what you will be able to cast but you also don't give your opponent a big pile of new cards either. These are both huge advantages that are a little offset by needing to make use of the cards in your graveyard in one turn only and needing to have them there in the first place. Typically you want to use the huge card advantage spells as the last things you cast and so these minor drawbacks are least noticeable when Will is optimally used. The reason Will is so abusive with access to the power is mostly just Black Lotus which is highly unfair and allows much quicker abuses of Will. The other fast mana from Moxen and Sol Ring helps too but doesn't have quite the same synergy. Dark Ritual and Lake of the Dead are still available and work similarly to Black Lotus if not quite so well. The cheaper your deck the better Yawmoth's Will becomes making it far better in combo and agro decks than control. In combo Will is especially useful as it is a generic recursion spell in black which typically is only able to recur creatures. In singleton formats the ability to get back a key card is pretty huge, the fact that this is neatly bolted on to a hugely efficient card advantage spell compounds the cards power.
Wrath of God in black is a pleasant treat and gives black one of the most effective ranges of creature kill. White has the largest abundance of mass removal and red has a wide array of costs for mass removal effects however all red ones deal damage and all the best white ones are destroy effects. With Damnation black has -X/-X, sacrifice and good destroy effects available to it. Without Damnation black would suffer a little like red does with cheap but highly situational mass removal and overcosted more certain mass removal. Having a range of ways to kill things complete with good tutor effects allows black to control creature decks with mass removal better than any other colour despite the extra redundancy white has. Damnation, as with Wrath of God is the best and most reliable all round mass removal you can get which allows few creatures to escape and costs a reasonable amount. Damnation is a key card in black and blue black control decks, it crops up in the odd slower combo deck and a great time saver and out card, I have even seen it played to good effect in the most extreme control builds of the rock.
Nether Void 1.5
Perpetual Gloom for all and sundry is what this card brings to the game. Black has the best tools to really abuse this card with the ability to pull cheaper cards out of the hand before getting to cast and hitting lands with Sinkhole and Smallpox. Black also has some very cheap yet powerful threats such as Bitterblossom or Nantuko Shade or threats that don't need casting like Bloodghast. The thing I have found is that the support cards are enough and that Nether Void tends to end up being a win more card or dead weight in your hand wishing it were a threat or a removal spell. Artifact decks are another natural home for the Void with their fast mana however those are already fairly inconsistent decks that suffer too much by putting in situational cards. Four is also a bit too steep and allows too much to happen before it comes down making cards like Sphere of Resistance much better in this sort of role.
Living Death 2.5
An extremely powerful effect that is not all that hard to set up. It is a little too unpredictable to see play in decks not designed around it with a selection of discard outlets, ways to sacrifice creatures in play and ideally ways to take things out of the opponents graveyard too. The Rock can easily achieve these ends and can be built to make good use of the card although this has fallen out of favour simply because Birthing Pod is newer and therefore more fun. Typical reanimator decks are also well equipped to pack Living Death and don't really even need to worry about what their opponents might get back as they wont have killed much and will have way better dorks coming back. It serves as a really good backup plan should your cheap single target reanimation attempts not get the job done. I have not yet seen a dedicated turbo Living Death style combo deck which doesn't surprise me as it would be far less robust than either of the other homes for Living Death and a clear tier 2 deck complete with loads of dregs from the C cube.
Sorin Markov 3.0
Sorin has been rather overshadowed by Grave Titan in the 6 slot and doesn't see all that much play any more. When he was first added he was getting played in all but the most agro of black decks and dominating a lot of games. His extravagant 6 mana cost complete with triple black requirements would be quite prohibitive in most other colours but with Lake of the Dead and Dark Ritual Sorin is suitably playable and feels more like a 5 mana walker. Sorin is a very nicely rounded walker and does a lot of things black really wants. Life gain is huge in black and usually equates to more cards Being able to kill little critters, reduce other walkers faster than they can grow or just nibble away while gaining life and throwing two extra loyalty on Sorin is a huge tempo swing and an ideal option for black. Making a Life total 10 is quirky and is useful more often than you might expect. Gaining infinite life is not unheard of in the cube for which this is a good answer, sometimes it even just speeds up a kill by several turns when the game swings in your favour. The ultimate is quite easy to pull off with Sorin growing so effectively and protecting himself well and gives black a lot of ways to deal with things it otherwise struggles with. Like most ultimates using it tends to seal the deal although the few uses of the +2 ability have quite a lot to do with that. Having now played a bit with Sorin's smaller golden incarnation I am not too concerned about this Sorin losing slots due to the other getting them as the Lord of Innistrad is never played over Elspeth at present. Markov is rather under rated and while not the best planeswalker is still just about in the top 10 walkers which is a powerful place to be.
Yawgmoth's Bargain 3.5
When combo was more common and the cube was powered Bargain was better than Necropotence. As creature decks have dominated the doubly expensive mana cost of Bargain over Necro does not outweigh the advantages Bargain offers. Bargain gives you your cards immediately which makes everything at least a turn quicker as well as giving you much better information at all times so as to allow optimal decisions about what to draw. It is pretty hard to lose a game when you have a Bargain in play and are not under imminent threat of death. Getting to 6 mana while remaining far from death is very tough in the cube and so Bargain has fallen a little out of favour, especially as you could make Sorin or Grave Titan for that 6 mana, regain some immediate tempo and stand a good chance of winning that way instead. If you can cheat it into play with an Academy Rector it looks a lot more appealing otherwise you want a robust control deck or lots of ramp to be able to get away with it. Mono black agro could run it as redundancy for Necro with the help of Lake of the Dead and Dark Ritual however it might as well play a tutor for redundancy. Despite its slightly prohibitive costs Bargain remains the best card draw in magic being able to quickly draw more cards for less mana than any other (you have to draw a lot of cards to out do the efficiency of Ancestral Recall but it is still possible!) and should not be overlooked even in these periods of decline.
Mind Twist 3.0
Powerful, but not as much as many seem to think. For mana efficiency I generally prefer to run Hymn to Tourach as discard, especially random, is best early. Mind Twist can be devastating if you can wipe out their entire hand (say 3 or 4 cards) in the early mid game where the tempo difference is not too extreme. When this happens you have to be very unlucky to then lose. As with any discard spells they become utterly useless most of the time a game goes late, which for an X spell is a little counter synergic. They are also like card draw spells in that they don't advance your board position at all which means you only want to cast them when things are stable. To get the best use out of Twist you often have to make some other sacrifices which means the card is quite interesting to play despite being very dull to play against. A clunky card that is narrow and offers no tempo but makes up for this with potential game winning power.
Death Cloud 4.5
In terms of the power of the effect Death Cloud is up there with some really big names such as Upheaval and Balance. It is one of my favourite spells and one of the most underrated cards in the cube. In many ways it is the black command because it does so many things so well. The majority of games I win with black decks are the direct result of casting a Cloud which I play in basically every heavy black deck I build from agro through to control (although sadly not in the few combo decks that float about). Considering the power and versatility of the card it does not cost all that much and is as effective when cast with X being one or two as it is when X is 4 or more (obviously depending on the game state). It gives black decks so much reach like Overrun for green but more so. It is an interesting card as you sometimes have to engineer the game state so that you can make most use of the Cloud, you also have difficult choices about what sacrifices to make yourself in order to do more damage to your opponent. Death Cloud can basically mimic the effects of all of the following cards: Innocent Blood, Damnation, Armageddon, Strip Mine, Mind Twist, Balance and Fireball. Frequently I end up using it as a bad burn spell to end a game my opponent fell to too low a life total in. It is just so easy to pay the appropriate amount for X and end up ahead or at least back to even footing in a game you were very behind in. You can exploit any aspect of the game in which you have an advantage be that in creature count, lands in play, life totals or cards in hand. Mono black agro is probably the second best agro deck in my cube at present after red deck wins which is further biased due the favourable matchup burny decks have against self inflicting pain style black decks. Many people say black is the weakest cube colour and I suspect much of this is due to people not auto including the Cloud in their decks. Black is a narrow colour but it is far far from weak. To highlight the power of Death Cloud further and for those that remember the format, I used a mono black agro deck in Mirrodin block constructed to qualify for my first pro tour. This was a format dominated by affinity and Tooth and Nail as well as a viable mid range red deck. All of those decks should be able to destroy a limp mono black deck using Blind Creepers and Slith Bloodletters to beatdown except for the abusive power of the Cloud. Pick it, play it and win, my promise to you, the faithful reader.