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.)

Library of Lat-Nam

An opponent chooses one —
• You draw three cards at the beginning of the next turn's upkeep.
• You search your library for a card, put that card into your hand, then shuffle.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Tromokratis

Tromokratis has hexproof unless it's attacking or blocking.
Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Noble Benefactor

When Noble Benefactor dies, each player may search their library for a card and put that card into their hand. Then each player who searched their library this way shuffles.

Nadir Kraken

Whenever you draw a card, you may pay {1}. If you do, put a +1/+1 counter on Nadir Kraken and create a 1/1 blue Tentacle creature token.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Merchant of Secrets

When Merchant of Secrets enters the battlefield, draw a card.

Merchant Scroll

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

Syr Elenora, the Discerning

Syr Elenora, the Discerning's power is equal to the number of cards in your hand.
When Syr Elenora enters the battlefield, draw a card.
Spells your opponents cast that target Syr Elenora cost {2} more to cast.

Gryff Vanguard

Flying
When Gryff Vanguard enters the battlefield, draw a card.

Fallowsage

Whenever Fallowsage becomes tapped, you may draw a card.

Reservoir Kraken

Trample, ward {2}
At the beginning of each combat, if Reservoir Kraken is untapped, any opponent may tap an untapped creature they control. If they do, tap Reservoir Kraken and create a 1/1 blue Fish creature token with "This creature can't be blocked."

Llawan, Cephalid Empress

When Llawan, Cephalid Empress enters the battlefield, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Genesis Chamber

Whenever a nontoken creature enters the battlefield, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Sea Kings' Blessing

One or more target creatures become blue until end of turn.

Palace Familiar

Flying
When Palace Familiar dies, draw a card.

Purple-Crystal Crab

When Purple-Crystal Crab dies, draw a card.

Dizzy Spell

Target creature gets -3/-0 until end of turn.
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.)

Gadwick, the Wizened

When Gadwick, the Wizened enters the battlefield, draw X cards.
Whenever you cast a blue spell, tap target nonland permanent an opponent controls.

Thopter Assembly

Flying
At the beginning of your upkeep, if you control no Thopters other than Thopter Assembly, return Thopter Assembly to its owner's hand and create five 1/1 colorless Thopter artifact creature tokens with flying.

Filigree Familiar

When Filigree Familiar enters the battlefield, you gain 2 life.
When Filigree Familiar dies, draw a card.

Kingfisher

Flying
When Kingfisher dies, draw a card.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Long-Term Plans

Search your library for a card, then shuffle and put that card third from the top.

Defiler of Dreams

Flying
As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay.
Whenever you cast a blue permanent spell, draw a card.

Muse Drake

Flying
When Muse Drake enters the battlefield, draw a card.

Library Larcenist

Whenever Library Larcenist attacks, draw a card.

Trove Tracker

When Trove Tracker dies, draw a card.
Encore {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Body of Knowledge

Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever Body of Knowledge is dealt damage, draw that many cards.

Aether Channeler

When Aether Channeler enters the battlefield, choose one —
• Create a 1/1 white Bird creature token with flying.
• Return another target nonland permanent to its owner's hand.
• Draw a card.

Illusory Ambusher

Flash (You may cast this spell any time you could cast an instant.)
Whenever Illusory Ambusher is dealt damage, draw that many cards.

Howling Golem

Whenever Howling Golem attacks or blocks, each player draws a card.

Illusory Angel

Cast this spell only if you've cast another spell this turn.
Flying

Tome Raider

Flying
When Tome Raider enters the battlefield, draw a card.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Exultant Cultist

Sway of Illusion

Any number of target creatures become the color of your choice until end of turn.
Draw a card.

Runewing

Micromancer

When Micromancer enters the battlefield, you may search your library for an instant or sorcery card with mana value 1, reveal it, put it into your hand, then shuffle.

Fblthp, the Lost

When Fblthp, the Lost enters the battlefield, draw a card. If it entered from your library or was cast from your library, draw two cards instead.
When Fblthp becomes the target of a spell, shuffle Fblthp into its owner's library.

Distant Memories

Search your library for a card, exile it, then shuffle. Any opponent may have you put that card into your hand. If no player does, you draw three cards.

Oneirophage

Flying
Whenever you draw a card, put a +1/+1 counter on Oneirophage.

Nimble Innovator

When Nimble Innovator enters the battlefield, draw a card.

Darkslick Drake

Flying
When Darkslick Drake dies, draw a card.

Jeskai Sage

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Jeskai Sage dies, draw a card.