Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Blue Elemental Blast

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

Of One Mind

This spell costs {2} less to cast if you control a Human creature and a non-Human creature.
Draw two cards.

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}.)

Aether Spellbomb

{U}, Sacrifice this artifact: Return target creature to its owner's hand.
{1}, Sacrifice this artifact: Draw a card.

Negate

Murmuring Mystic

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

Augur of Bolas

When this creature enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

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.)

Cryptic Serpent

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

Island

Bird Illusion

Counterspell

Brainstorm

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

Consider

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