Kuznar, Pontiff of Shadows

Eminence - At the beginning of each end step, if Kuznar, Pontiff of Shadows is in the command
zone or on the battlefield, if you gained 3 or
more life this turn, create a 2/2 black Rogue
creature token with menace.
At the beginning of your upkeep, you may
sacrifice a creature. If you do, each opponent
loses X life and you gain X life, where X is equal
to the sacrificed creature's toughness.