Arcane Thief Cain

Deathtouch, Unblockable
When this creature deals combat damage to a player, look at the top three cards of that players library, then exile one and put the rest on the bottom in random order.
{x}: Cast a non-creature, non-planeswalker card exiled by Cain with converted mana cost X or less.
{1}{u}: Return Arcane Thief Cain to your hand.