X-Men Genesis

Exile all creatures you control, then reveal cards from the top of your library until you reveal that many creature cards. Cast those creature cards revealed this way without paying it's mana cost, then shuffle the rest of the revealed cards into your library.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)