Spells and abilities your opponents control can't cause their controller to search their library.

−1: Target player mills four cards. Then exile each opponent's graveyard.

+2: Exile the top three cards of target opponent's library.

−X: Put a creature card with mana value X exiled with Ashiok, Nightmare Weaver onto the battlefield under your control. That creature is a Nightmare in addition to its other types.

−10: Exile all cards from all opponents' hands and graveyards.

If you would pay life while your library has at least that many cards in it, exile that many cards from the top of your library instead.

+1: Look at the top two cards of your library. Exile one of them and put the other into your hand.

−2: Create two 1/1 black Nightmare creature tokens with "At the beginning of combat on your turn, if a card was put into exile this turn, put a +1/+1 counter on this creature."

−7: Target player exiles the top X cards of their library, where X is the total mana value of cards you own in exile.

Flash

When Ashiok's Erasure enters, exile target spell.

Your opponents can't cast spells with the same name as the exiled card.

When Ashiok's Erasure leaves the battlefield, return the exiled card to its owner's hand.

Whenever an enchantment you control is put into a graveyard from the battlefield, draw a card.