Sacrifice Tenacious Dead to Ashnod's Altar, generating ({2} magic symbol) .
Pitiless Plunderer, Zulaport Cutthroat, and Tenacious Dead trigger; stack the triggers to resolve in that order.
Pitiless Plunderer generates a Treasure token; crack it to float ({B} magic symbol) .
Zulaport Cutthroat drains each opponent for 1.
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, floating ({1} magic symbol) with each iteration and draining opponent infinitely with Zulaport Cutthroat triggers.