Yorion, Sky Nomad (Serial Numbered)

Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (If this card is your chosen companion, you may put it into your hand from outside the game for 3 as a sorcery.)
Flying
When Yorion enters the battlefield, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step.