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.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Thassa's Oracle

When Thassa's Oracle enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Murmuring Mystic

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

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.)

Isochron Scepter

Imprint — When Isochron Scepter enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Crystal Shard

{3}, {T} or {U}, {T}: Return target creature to its owner's hand unless its controller pays {1}.

Equilibrium

Whenever you cast a creature spell, you may pay {1}. If you do, return target creature to its owner's hand.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Drowned Secrets

Whenever you cast a blue spell, target player mills two cards.

Personal Tutor

Search your library for a sorcery card, reveal it, then shuffle and put that card on top.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Merchant Scroll

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

Flare of Denial

You may sacrifice a nontoken blue creature rather than pay this spell's mana cost.
Counter target spell.

Forensic Gadgeteer

Whenever you cast an artifact spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Activated abilities of artifacts you control cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Trade Routes

{1}: Return target land you control to its owner's hand.
{1}, Discard a land card: Draw a card.

Mindsplice Apparatus

Flash
At the beginning of your upkeep, put an oil counter on Mindsplice Apparatus.
Instant and sorcery spells you cast cost {1} less to cast for each oil counter on Mindsplice Apparatus.

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Island

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

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.)

Thought Vessel

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

Dramatic Reversal

Untap all nonland permanents you control.

Engulf the Shore

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

Braingeyser

Peregrine Drake

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

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Ponder

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

Temporal Trespass

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Take an extra turn after this one. Exile Temporal Trespass.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

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}.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Seal of Removal

Sacrifice Seal of Removal: Return target creature to its owner's hand.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

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.)

Helm of Awakening

Brainstorm

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

Jace's Sanctum

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, scry 1.

Cloud Key

As Cloud Key enters, choose artifact, creature, enchantment, instant, or sorcery.
Spells you cast of the chosen type cost {1} less to cast.

Ghostly Flicker

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

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Spellbook

Consider

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

Teferi's Tutelage

When Teferi's Tutelage enters, draw a card, then discard a card.
Whenever you draw a card, target opponent mills two cards. (They put the top two cards of their library into their graveyard.)

Jace, Wielder of Mysteries

If you would draw a card while your library has no cards in it, you win the game instead.
+1: Target player mills two cards. Draw a card.
−8: Draw seven cards. Then if your library has no cards in it, you win the game.

Sapphire Medallion

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

Thunderclap Drake

Flying
Instant and sorcery spells you cast cost {1} less to cast.
{2}{U}, Sacrifice Thunderclap Drake: When you next cast an instant or sorcery spell this turn, copy it for each time you've cast your commander from the command zone this game. You may choose new targets for the copies.

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Basalt Monolith

Basalt Monolith doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap Basalt Monolith.

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Fblthp, the Lost

When Fblthp, the Lost enters, 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.

Aether Channeler

When Aether Channeler enters, 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.

Extraplanar Lens

Imprint — When Extraplanar Lens enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Solve the Equation

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

Serum Visions

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

Gitaxian Probe

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

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Rings of Brighthearth

Whenever you activate an ability, if it isn't a mana ability, you may pay {2}. If you do, copy that ability. You may choose new targets for the copy.