Obcasus Phyrex, Death Seeker

Vigilance, hexproof
You can't lose the game by poison counters.
Whenever Obcasus attacks or blocks, you get a
poison counter. During your upkeep, each player
chooses one: Sacrifice a permanent, discard a
card, or pay {p/b}.
{x}{p/b}{p/b}: Remove X poison counters and gain X
life. Where X is the number of counters removed
this way.