Counterspell

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Island

Lose Focus

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Counter target spell unless its controller pays {2}.

Serpentine Curve

Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is one plus the total number of instant and sorcery cards you own in exile and in your graveyard.

Tolarian Terror

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Dispel

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Tome Scour

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Foil

You may discard an Island card and another card rather than pay this spell's mana cost.
Counter target spell.

Thought Scour

Target player mills two cards.
Draw a card.

Unsummon

Return target creature to its owner's hand.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.