Mono-Black cube, designed to be eventually drafted by the wacky mages of the XMage Historical Draft Society.

Black can do it all- aggro, midrange, control, and combo! Can this cube do all those things? I dunno, probably?

First, a couple of general points- Black is good at a lot of things, but it's not good at removing noncreature permanents. (Sinkhole isn't in this cube) I've attempted to balance this by not having too many completely unbeatable artifacts and enchantments, but in case some things slipped through, there's meteor golem, lux cannon, and clay golem. Enchantment removal in Black is also a little sketchy, but we have pretty much all of them- Feed the Swarm, Debt to the Kami, Pharika's Libation.

Secondly, Black can do pretty much anything... but you'll pay for it in blood. The aggro decks are out there just waiting to pounce after you've hit necropotence or yawgmoth's bargain or even read the bones a few too many times. Normally you wouldn't think twice about cracking a sign in blood turn 2, but those incidental life taps can add up... You can deal with this by picking up some cards that gain life, killing your opponent before your own sad life total matters, or through cards like Death's Shadow or Scourge of the Skyclaves that encourage you to live on the edge. Of course, there's also mirror universe!

There are multiple archetypes to explore in this cube, and I'll start off with Aggro. Black has several very good recursive savannah lions, like dread wanderer and champion of the bloodstained. Combined with anthems like Paragon of Open Graves or Hall of Triumph, you can get a surprising amount of sheer damage through combat pretty fast. Make sure to look out for reach though- with the amount of removal running around, I suspect you'll be hitting your opponent with something like foreboding fruit to get those last bits of damage through. Some other good options? Zombie Trailblazer and Dauthi Trapper.

Within Aggro there are two powerful tribes, Zombies and Vampires. Both skew aggressive, but have very powerful tribal lords and their own flavor. Instead of going wide with Zombies, you're looking to make them impossible to block with things like Graf Harvest or Zombie Master while making them huge with lords. Vampires can look towards a slight lifegain theme with Sanctum Seeker and Malakir Bloodwitch, which make racing very difficult for your opponents. There's also Vampire Nocturnus, which is most of the time an insane flying anthem since your deck is mono-black.

In the Midrange slot we have your standard good rate creatures and removal piles, but also aristocrats. Zulaport Cutthroat, Bastion of Rememberance, and Falkenrath Noble are all in this cube, and with support like Viscera Seer and Woe Strider they can threaten large drains which will keep your opponent guessing. There's even the poor man's Return to the Ranks in Agadeem's Awakening! I wouldn't consider aristocrats to be a whole draftable archetype, but in a deck with a flexible plan like midrange it probably shines the best.

In the combo slot there are two main options- Reanimator, which is probably the competitive one, and Storm, which is the fun one. Your classic Entomb+Reanimate is in this cube, along with Dark Ritual if you want to be really evil and do it on turn 1. For targets you have everyone's favorite demon Griselbrand, but also Archon of Cruelty or even Archfiend of Despair. Getting a Myr Battlesphere or Dreadfeast Demon isn't bad either. Just watch out for unconditional creature removal, of which Black has quite a bit of.

Storm is a bit more tricky. You'll need the normal surplus of card draw and mana, but payoff-wise there's really only one choice- Tendrils of Agony. However, with the presence of two mana-doublers in the cube (Bubbling muck and Rain of Filth), you can also run a huge mana deck, looking to eventually win with an enormous Torment of Hailfire or even Walking Ballista. Grab those tutors whenever you can, and try to find some lifegain as well- you'll need all the time you can get to set up your giant turn.

As an aside, it's really hard, if not impossible, for black to interact with some of the less creature-focused combos. Outside of things like Relic of Progenitus against reanimator, your main chance to interact will be by limiting their life total. Just go kill them.

On the control side, I'll remind you that much of black card draw is tied into life loss. Be on the lookout for ways to regain that life, and for sweepers like Mutilate or even ones with card advantage attached like Feast of Succession. If you can get to the point where you're slamming down a Rune-Scarred Demon, you're probably doing pretty well. Don't forget about Nevinyrral's disk, as that's the most complete sweeper in the cube. Planeswalkers, as always, are pretty great.

One other way to take control is though a light discard theme. Thoughtseize, Duress, Wrench Mind, etc, are all in this cube. So are 8rack staples The Rack and Shrieking Affliction. Why not beat your opponent by ripping apart their hand while accruing advantage through cards like Waste Not?

Finally, a couple of combos I'm fond of and miscellaneous notes-
Exquisite blood + Vito (No sanguine bond, so you can at least try to interact)
Lose all your friends by playing Chittering Rats into Skull Collector
Lich + Ad Nauseum will let you draw your whole deck
Lich + Mirror Universe or Magus of the Mirror just wins if you untap
Stunning Reversal is the real deal, esp. for combo decks
Since the cube is mono-black, most of the interaction is kill spells. That makes something like Feign Death kind of a counterspell. They're not as bad as they look!
Have fun! There's probably some crazier interactions I missed, but that's up to you to find out! Draft a wacky deck, have a memorable time!

some quick themes-
reanimator- entomb, exhume, etc
discard- mind twist, davriel, shrieking affliction, the rack, tourach
storm?- card draw, tendrils of agony, rituals, tutors
vampires- cordial vampire, captivating vampire, vampire noctournus
zombies- lords, tokens, swampwalk (lol)
rats- ogre slumlord, marrow-gnawer, piper of the swarm
sacrifice- carrion feeder, Grave pact
aristocrats- zulaport cutthroat, bastion of remembrance
draw a bunch of cards- necropotence, Yawgmoth's Bargain, etc
lifegain- bloodthirsty aerialist, vampire nighthawk, etc
recursive aggro- bloodsoaked champion, dread wanderer, gutterbones
swamps matter- liliana of the dark realms, cabal coffers, dread prescence
devotion- gary, nykthos, sanguimancy
undercosted beaters- doom whisperer, demon of catastrophes, rotting regisaur

Notes from first playtest:
Aggro did feel maybe slightly too strong
Final punishment too weak
Deathbringer Regent perhaps too weak
Dauthi Trapper too weak
custodi lich out for thorn of the black rose