Death's Game

Whenever a creature you control dies, you may
exile it. When you do, put all other creature
cards exiled with Death's Game to their
owners' graveyards.
Whenever a creature you control deals combat
damage to a player, if you own a creature card
exiled with Death's Game, you may exile that
creature. When you do, return another creature
card exiled with Death's Game to the battlefield
under your control.