The Devourer

Begin the game with this card revealed.
During your upkeep, each play sacrifices
a nonland permanent. If they can't they
they lose 2 life.
Creatures you control have devour 1, except
you may sacrifice creatures other players control.
However, if you sacrifice other player's creatures
you lose 1 life for each and can't do it to players
who can only control one creature.
You cannot have or gain a win condition.