Torin, Archon of Misery

Misery- While Torin is in the command zone, whenever a creature dies, put a +1/+1 counter on it's killer

Menace

Whenever a creature dies you gain 1 life

Sacrifice a creature: Torin gains +X/+0 until end of turn, where X is the sacrificed creature's power, if this has happened more than five times this turn, put a trample counter on Torin