Pelmanism

Pelmanism (When this enters the battlefield, players mill 1 until the number of cards in their graveyard is not prime. Then, each player exiles the cards in their graveyard face down in a pile, shuffles it, and arranges it in rectangular matrix.)
{3}, Pay 1 life: Name a card. Then, reveal target face down card in exile. Return it to its owner's graveyard if names match. Then, if it was a spell, you may cast a copy of it as though it