Whenever a nontoken creature is put into your graveyard from the battlefield, exile that card.
At the beginning of your upkeep, you may pay

and 2 life. If you do, return a card exiled with this enchantment to the battlefield.
If this card changes controllers between putting the upkeep triggered ability on the stack and resolving it, the creature is put onto the battlefield under the control of the player who controlled this card when the ability was put on the stack.