Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Merchant Scroll

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

Merchant of Secrets

When Merchant of Secrets enters, draw a card.

Brainstorm

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

Aspiring Aeronaut

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Aspiring Aeronaut enters, create a 1/1 colorless Thopter artifact creature token with flying.

Voidwielder

When Voidwielder enters, you may return target creature to its owner's hand.

Augury Owl

Flying
When Augury Owl enters, scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Nimble Innovator

When Nimble Innovator enters, draw a card.

Island

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Counterspell

Merrow Witsniper

When Merrow Witsniper enters, target player mills a card.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Sky Diamond

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Witching Well

When Witching Well enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{3}{U}, Sacrifice Witching Well: Draw two cards.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Pristine Talisman

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Snap

Return target creature to its owner's hand. Untap up to two lands.

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Serum Visions

Mana Leak

Counter target spell unless its controller pays {3}.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Scrivener

When Scrivener enters, you may return target instant card from your graveyard to your hand.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Mist Raven

Flying
When Mist Raven enters, return target creature to its owner's hand.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Capsize

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return target permanent to its owner's hand.

Man-o'-War

When Man-o'-War enters, return target creature to its owner's hand.

Snapback

You may exile a blue card from your hand rather than pay this spell's mana cost.
Return target creature to its owner's hand.

Gryff Vanguard

Flying
When Gryff Vanguard enters, draw a card.

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Aether Adept

When Aether Adept enters, return target creature to its owner's hand.

Vapor Snag

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

Separatist Voidmage

When Separatist Voidmage enters, you may return target creature to its owner's hand.

Omenspeaker

When Omenspeaker enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Salvager of Secrets

When Salvager of Secrets enters, return target instant or sorcery card from your graveyard to your hand.

Boomerang

Return target permanent to its owner's hand.

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

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

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

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.)

Sage's Row Denizen

Whenever another blue creature you control enters, target player mills two cards.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Sea Gate Oracle

When Sea Gate Oracle enters, look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.