Mystic Chieftain

When Mystic Chieftain enters the battlefield,
look at the top four cards of your library and
separate them into a face-down pile and a face-up
pile. An opponent chooses one of those piles.
Manifest the cards in that pile and put the other
pile into your graveyard. (To manifest a card, put
it onto the battlefield face down as a 2/2 creature.
Turn it face up any time for its mana cost if it’s a
creature card.)