Masochistic Mutilator

When Masochistic Mutilator dies, you may pay 4 life. If you do, return Masochistic Mutilator to the battlefield tapped.
Lieutenant - Whenever Masochistic Mutilator and at least one other creature attacks, until end of combat you may sacrifice any number of Human creatures. Masochistic Mutilator deals X damage to target creature or player, where X is equal to the combined toughness of all creatures sacrificed this way.