Flippy, Fate Reverter

{w}{u}{b}{r}{g}, {t}: Flip all face down and double faced permanents you control.

Whenever a a double faced permanent you control is flipped to reveal an instant or sorcery card, exile that card and flip a coin. If you win the flip, you may cast the exiled card without paying its mana cost. If you lose, place it into its owner's graveyard.