Kryptor,The Corrupted One

+3: Sacrifice target creature you control. Deal X damage, or draw X cards where X is that creature's toughness.
-7: Gain control of target creature an opponent controls. Sacrifice it at your end step. It has haste and lifelink.
-20: Target player gets an emblem that says "At each upkeep, sacrifice a creature. Opponent who owns this emblem gains control of sacrificed creature.