Ashiok, Fae Intruder

: Whenever a creature you control deals combat damage to a player, that player exiles that many cards from the top of their library.
+1: Create a 1/1 blue and black Faerie Nightmare creature token with flying.
-X: Cast a card with mana value X exiled with Ashiok, Fae Intruder without paying its mana cost.