Have

Boomerang

Return target permanent to its owner's hand.

Mental Note

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Lórien Revealed

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

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

Brainstorm

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

Dispel

Spell Pierce

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

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Island

Consider

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

Force Spike

Counter target spell unless its controller pays {1}.

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}.)

Steel Sabotage

Choose one —
• Counter target artifact spell.
• Return target artifact to its owner's hand.

Thought Scour

Target player mills two cards.
Draw a card.

Echoing Truth

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

Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.