When Prodigious Seer enters the battlefield, each player manifests the top card of their library. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it’s a creature card.)

{U}, {T}: Look at target face-down permanent or face-down card in exile. If it’s not a creature and you own it, you may cast it. (You still pay its costs.)