Fithis, Origin of Incoherence

When Fithis, Origin of Incoherence enters the battlefield, target opponent looks at the bottom three cards of another target opponents library and chooses one to put at the bottom of its owners library. Put one of two cards at the top of its owner's library and exile the other face down, you may look at and play that card for as long as it remains exiled this way and you may spend mana as though it