Magician of the Event

When Magician of the Event enters the battlefield, exile the top seven cards from your library face down, then each opponent chooses a card exiled this way at random, you may cast those cards without paying their mana cost. Shuffle the rest back into your library.
"Ladies and gentlemen! For our next act, our magician will draw something from his hat, what will it be? a cute little bunny? A warm and bright candle? Or a 30 feet tall fire breathing dragon?"