Phyrexian Mindslavery

Players can't lose the game if they have 10 or
more poison counters.
You gain control of opponents with 10 or more
poison counters. Creatures controlled by these
players have Toxic 1 as long as that player has 10
or more poison counters.
Whenever a player gets a poison counter, if each
opponent has 10 or more poison counters, you
win the game.