Tenacious Dead | Phyrexian Altar | Sifter of Skulls

(and one other card)

Sacrifice
Tenacious Dead to
Phyrexian Altar, generating ({B} magic symbol) .
Sifter of Skulls,
Zulaport Cutthroat, and
Tenacious Dead trigger; stack the triggers to resolve in that order.
Sifter of Skulls generates an Eldrazi Scion token; sacrifice it to generate ({1} magic symbol) (
Zulaport Cutthroat triggers again).
Resolve two
Zulaport Cutthroat triggers, draining opponent for 2.
Resolve the
Tenacious Dead trigger, paying ({1} magic symbol) ({B} magic symbol) to return it to the battlefield from the graveyard.
Repeat the sacrifice-recursion loop, draining opponent infinitely with
Zulaport Cutthroat triggers.