Island

Counterspell

Spell Pierce

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

Brainstorm

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

Force Spike

Counter target spell unless its controller pays {1}.

Mental Note

Cryptic Serpent

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

Thought Scour

Target player mills two cards.
Draw a card.

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}.)

Consider

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

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

Stream of Thought

Target player mills four cards. You shuffle up to four cards from your graveyard into your library.
Replicate {2}{U}{U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)

Frantic Inventory

Draw a card, then draw cards equal to the number of cards named Frantic Inventory in your graveyard.