Vaax, Master of Misdirection

Each card you own that isn't on the battlefield has stealth. (You may cast a card with stealth face down as a 2/2 creature for {3}.)
Whenever a face down creature you control blocks, becomes blocked, deals combat damage to an opponent or becomes the target of a spell or ability, turn it face up. If it's a creature, return it to its owner's hand at end of turn. If it isn't a creature, exile it.