Manta, Absolute

+2: Sacrifice a permanent: Create X 2/2 black Demon creature tokens where X is the converted mana cost of the sacrificed permanent.
-2: Draw 4 cards, then discard 4 cards until you sacrifice 2 creatures.
-7: Destroy all nonland permanents, except Manta, the Absolute. Return all creatures from all graveyards to the battlefield under your control.