Mono Black Aristocrats
Repeatedly sacrifice and reanimate your own creatures to trigger all kinds of exciting effects. Mid to late game the deck can play with a ton of tempo and flexibility, allowing you to chain together triggers in a variety of ways.
Archfiend's Vessel: Great turn one play and reanimation target
Burglar Rat: Reanimation target and two drop for curve
Skirsdag High Priest: Fantastic die trigger payoff, but we don't want too many because we never want to sacrifice it and it's useless without a decent board state
Plaguecrafter: Solid reanimation target and sacrifice outlet in the three drop slot
Grim Haruspex: Good for dies triggers. Draw power is great in multiplayer :)
Ravenous Chupacabra: Great reanimation target at the top end of the curve
Fiend Artisan: Fantastic sacrifice outlet that also gives us a resource advantage (because sacrificing a creature isn't a disadvantage in this deck). It also allows us to tutor up key pieces that we need at any given time for example Skirsdag High Priest, Grim Haruspex, or Ravenous Chupacabra
Cavalier of Night: The card that inspired the deck! Has literally everything we want in one card - ETB for reanimation that's doubles as a sacrifice outlet, dies trigger for a payoff when sacrificed that oh just reanimates almost anything in the deck..
Victimize, Blood for Bones: sacrifice outlets that also reanimate stuff