Emrakul, Moon's Presence

Flying, Trample, Hexproof from colored spells
Inflict {6} -- You may cast this card for its
inflict cost as an aura curse enchanting target opponent.
If this card leaves the battlefield, return it to the battlefield under your control as a creature.
At the beginning of enchanted player's upkeep,
that player sacrifices a creature. If they can't,
Emrakul, Moon's Presence return's to its owner's control as a creature.