Whenever you cast a creature spell, create X 1/1 black Thrull creature tokens, where X is that spell's mana value.
When you control seven or more Thrulls, sacrifice Endrek Sahr.
Flood the board with Thrull tokens by casting creature spells, then convert that mass of bodies into damage or a combo kill before Endrek's seven-Thrull check sacrifices him. You build wide quickly, leverage sac outlets and payoffs, and close with an explosive turn.
Generates a huge volume of token bodies extremely fast, often making more value than you spend
Cheap creature spells snowball into board presence that fuels aristocrats and overrun strategies
Mono-black gives access to elite tutors, ramp, and recursion to find your payoffs
The seven-Thrull trigger forces Endrek to sacrifice himself, requiring active management
Token-based, so vulnerable to board wipes that erase your whole engine
Mono-black struggles to interact with the stack and remove problematic noncreature permanents
Endrek dies on his own often, costing you commander tax and consistency
Discounts creature spells and drains opponents whenever you cast them.
Add fast mana (Dark Ritual, Jet Medallion) and tutors (Demonic Tutor, Vampiric Tutor) to assemble sac-outlet combos faster. Lean into a dedicated aristocrats loop—Pitiless Plunderer plus Ashnod's Altar and a Blood Artist effect closes games—and include recursion like Victimize or Reanimate to rebuild after wraths. Prioritize cheap creatures so Endrek's Thrull output outpaces what you spend.