Have

Crab Umbra

Enchant creature
{2}{U}: Untap enchanted creature.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Kraken Hatchling

Reef Worm

When this creature dies, create a 3/3 blue Fish creature token with "When this token dies, create a 6/6 blue Whale creature token with 'When this token dies, create a 9/9 blue Kraken creature token.'"

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Mnemonic Wall

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

Stitcher Geralf

{2}{U}, {T}: Each player mills three cards. Exile up to two creature cards put into graveyards this way. Create an X/X blue Zombie creature token, where X is the total power of the cards exiled this way.

Wall of Frost

Defender
Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step.

Sol Ring

Stormtide Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
All lands are Islands in addition to their other types.
Creatures without flying or islandwalk can't attack.

Gleaming Barrier

Defender
When this creature dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Vizier of Tumbling Sands

{T}: Untap another target permanent.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle this card, untap target permanent.

Perplexing Test

Choose one —
• Return all creature tokens to their owners' hands.
• Return all nontoken creatures to their owners' hands.

Fog Bank

Defender (This creature can't attack.)
Flying
Prevent all combat damage that would be dealt to and dealt by this creature.

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Havengul Runebinder

{2}{U}, {T}, Exile a creature card from your graveyard: Create a 2/2 black Zombie creature token, then put a +1/+1 counter on each Zombie creature you control.

Charix, the Raging Isle

Spells your opponents cast that target Charix cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Floodgate

Defender
When this creature has flying, sacrifice it.
When this creature leaves the battlefield, it deals damage to each nonblue creature without flying equal to half the number of Islands you control, rounded down.

Wall of Deceit

Defender (This creature can't attack.)
{3}: Turn this creature face down.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

High Tide

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

Wall of Runes

Defender (This creature can't attack.)
When this creature enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Defabricate

Choose one —
• Counter target artifact or enchantment spell. If a spell is countered this way, exile it instead of putting it into its owner's graveyard.
• Counter target activated or triggered ability.

Academy Wall

Defender
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card. This ability triggers only once each turn.

Corridor Monitor

When this creature enters, untap target artifact or creature you control.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

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.

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Favorable Winds

Creatures you control with flying get +1/+1.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Shield Sphere

Defender
Whenever this creature blocks, put a -0/-1 counter on it.

Ancient Crab

Consulate Skygate

Defender
Reach (This creature can block creatures with flying.)

Guardians of Meletis

Murmuring Phantasm

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Energy Tap

Tap target untapped creature you control. If you do, add an amount of {C} equal to that creature's mana value.

Blue Sun's Twilight

Gain control of target creature with mana value X or less. If X is 5 or more, create a token that's a copy of that creature.

Ghostly Touch

Enchant creature
Enchanted creature has "Whenever this creature attacks, you may tap or untap target permanent."

In Too Deep

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Enchant creature, planeswalker, or Clue
Enchanted permanent is a colorless Clue artifact with "{2}, Sacrifice this artifact: Draw a card" and loses all other abilities. (It's no longer a creature or planeswalker.)

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Wall of Mist

Geralf, Visionary Stitcher

Zombies you control have flying.
{U}, {T}, Sacrifice another nontoken creature: Create an X/X blue Zombie creature token, where X is the sacrificed creature's toughness.

Aegis Turtle

Skaab Ruinator

As an additional cost to cast this spell, exile three creature cards from your graveyard.
Flying
You may cast this card from your graveyard.

Negate

Corrupted Grafstone

This artifact enters tapped.
{T}: Choose a color of a card in your graveyard. Add one mana of that color.

Riptide Turtle

Phyrexian Soulgorger

Cumulative upkeep—Sacrifice a creature. (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.)

Pull from the Deep

Return up to one target instant card and up to one target sorcery card from your graveyard to your hand. Exile Pull from the Deep.

Walking Wall

Defender
{3}: This creature gets +3/-1 until end of turn and can attack this turn as though it didn't have defender. Activate only once each turn.

Profaner of the Dead

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, return to their owners' hands all creatures your opponents control with toughness less than the exploited creature's toughness.

Scourge of Fleets

When this creature enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Kelpie Guide

{T}: Untap another target permanent you control.
{T}: Tap target permanent. Activate only if you control eight or more lands.

Ioreth of the Healing House

{T}: Untap another target permanent.
{T}: Untap two other target legendary creatures.

Steel Wall

Archaeomancer

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

Pull from Tomorrow

Midnight Clock

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

Fractured Powerstone

{T}: Add {C}.
{T}: Roll the planar die. Activate only as a sorcery.

Frantic Search

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

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Lonely Sandbar

This land enters tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Wall of Water

Defender (This creature can't attack.)
{U}: This creature gets +1/+0 until end of turn.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Cleaver Skaab

{3}, {T}, Sacrifice another Zombie: Create two tokens that are copies of the sacrificed creature.

Glacial Wall

Riptide Laboratory

{T}: Add {C}.
{1}{U}, {T}: Return target Wizard you control to its owner's hand.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Coral Colony

Defender
{1}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender. (To mill a card, a player puts the top card of their library into their graveyard.)

Amaranthine Wall

Defender
{2}: This creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Aetherize

Return all attacking creatures to their owner's hand.

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Noble's Purse

This artifact enters tapped and with three coin counters on it.
{T}, Remove a coin counter from this artifact: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Dragon's Eye Savants

Morph—Reveal a blue card in your hand. (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, look at target opponent's hand.

Confounding Conundrum

When this enchantment enters, draw a card.
Whenever a land an opponent controls enters, if that player had another land enter the battlefield under their control this turn, they return a land they control to its owner's hand.

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Hover Barrier

Wall of Junk

Defender (This creature can't attack.)
When this creature blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Decanter of Endless Water

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

Aboshan's Desire

Enchant creature
Enchanted creature has flying.
Threshold — Enchanted creature has shroud as long as seven or more cards are in your graveyard. (It can't be the target of spells or abilities.)

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Fortress Crab

Thought Vessel

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

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Iceberg Cancrix

Whenever another snow permanent you control enters, you may have target player mill two cards.

Explorer's Scope

Whenever equipped creature attacks, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Excavated Wall

Defender
{1}, {T}: Mill a card. (Put the top card of your library into your graveyard.)

Aether Gale

Return six target nonland permanents to their owners' hands.

Wall of Air

Defender, flying (This creature can't attack, and it can block creatures with flying.)

Tide Drifter

Devoid (This card has no color.)
Other colorless creatures you control get +0/+1.

Secret Door

Defender
{4}{U}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Island

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.