Chong Wu, Deity of Mt. Yi Wang

{1}{g}: Target card in hand gains the ability
"Hideaway" until the end of turn. (This card
enters the battlefield tapped. When it does, look
at the top four cards of your library, exile one
face down, then put the rest on the bottom of
your library.)
When this card leaves the battlefield, put all
faced down exile cards into your hand.