Sa'Kael, Heaven's Betrayer

Flying , Vigilance
Whenever Sa'Kael, Heaven's Betrayer enters the battlefield, you may chose one :
•Sacrifice another creature you control : until the next end step, you may cast target permanent in your graveyard with mana value 5 or less. It gains haste and has : "When this card leaves the battlefield, exile it. Sacrifice this card at the next end step."
•Discard a card : Target an instant or sorcery card in your graveyard with mana value 3 or less and cast it without paying it's mana cost.