Mist-Syndicate Naga

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Mist-Syndicate Naga deals combat damage to a player, create a token that's a copy of Mist-Syndicate Naga.

Sower of Temptation

Flying
When Sower of Temptation enters the battlefield, gain control of target creature for as long as Sower of Temptation remains on the battlefield.

Thran Dynamo

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Spiketail Hatchling

Flying (This creature can't be blocked except by creatures with flying or reach.)
Sacrifice Spiketail Hatchling: Counter target spell unless its controller pays {1}.

Serpent of Yawning Depths

Krakens, Leviathans, Octopuses, and Serpents you control can't be blocked except by Krakens, Leviathans, Octopuses, and Serpents.

Vexing Gull

Grappling Hook

Equipped creature has double strike.
Whenever equipped creature attacks, you may have target creature block it this turn if able.
Equip {4}

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Grand Architect

Other blue creatures you control get +1/+1.
{U}: Target artifact creature becomes blue until end of turn.
Tap an untapped blue creature you control: Add {C}{C}. Spend this mana only to cast artifact spells or activate abilities of artifacts.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Chronozoa

Flying
Vanishing 3 (This creature enters the battlefield with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Chronozoa dies, if it had no time counters on it, create two tokens that are copies of it.

Barrin, Tolarian Archmage

When Barrin, Tolarian Archmage enters the battlefield, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Perplexing Chimera

Whenever an opponent casts a spell, you may exchange control of Perplexing Chimera and that spell. If you do, you may choose new targets for the spell. (If the spell becomes a permanent, you control that permanent.)

Basalt Monolith

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

Wall of Kelp

Defender (This creature can't attack.)
{U}{U}, {T}: Create a 0/1 blue Plant Wall creature token with defender named Kelp.

Oneirophage

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

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Caged Sun

As Caged Sun enters the battlefield, 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.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Buried Ruin: Return target artifact card from your graveyard to your hand.

Teferi, Mage of Zhalfir

Flash
Creature cards you own that aren't on the battlefield have flash.
Each opponent can cast spells only any time they could cast a sorcery.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Inquisitor's Flail

If equipped creature would deal combat damage, it deals double that damage instead.
If another creature would deal combat damage to equipped creature, it deals double that damage to equipped creature instead.
Equip {2}

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.

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis the Omnipotent to its owner's hand.

Nezahal, Primal Tide

This spell can't be countered.
You have no maximum hand size.
Whenever an opponent casts a noncreature spell, draw a card.
Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Mulldrifter

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

Sword of Vengeance

Equipped creature gets +2/+0 and has first strike, vigilance, trample, and haste.
Equip {3}

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.

Simic Manipulator

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
{T}, Remove one or more +1/+1 counters from Simic Manipulator: Gain control of target creature with power less than or equal to the number of +1/+1 counters removed this way.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Glen Elendra Archmage

Flying
{U}, Sacrifice Glen Elendra Archmage: Counter target noncreature spell.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Fatespinner

At the beginning of each opponent's upkeep, that player chooses draw step, main phase, or combat phase. The player skips each instance of the chosen step or phase this turn.

Urza, Lord High Artificer

When Urza, Lord High Artificer enters the battlefield, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."
Tap an untapped artifact you control: Add {U}.
{5}: Shuffle your library, then exile the top card. Until end of turn, you may play that card without paying its mana cost.

Hall of Triumph

As Hall of Triumph enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+1.

Prophetic Prism

When Prophetic Prism enters the battlefield, draw a card.
{1}, {T}: Add one mana of any color.

Pondering Mage

When Pondering Mage enters the battlefield, look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

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.

Quicksilver Elemental

{U}: Quicksilver Elemental gains all activated abilities of target creature until end of turn. (If any of the abilities use that creature's name, use this creature's name instead.)
You may spend blue mana as though it were mana of any color to pay the activation costs of Quicksilver Elemental's abilities.

Emry, Lurker of the Loch

This spell costs {1} less to cast for each artifact you control.
When Emry, Lurker of the Loch enters the battlefield, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

River Kelpie

Whenever River Kelpie or another permanent enters the battlefield from a graveyard, draw a card.
Whenever a player casts a spell from a graveyard, draw a card.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Island

Cursecatcher

Sacrifice Cursecatcher: Counter target instant or sorcery spell unless its controller pays {1}.

Sapphire Medallion

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

Dolmen Gate

Prevent all combat damage that would be dealt to attacking creatures you control.

Cryptoplasm

At the beginning of your upkeep, you may have Cryptoplasm become a copy of another target creature, except it has this ability.

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}

Tribute Mage

When Tribute Mage enters the battlefield, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Sea-Dasher Octopus

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flash
Whenever this creature deals combat damage to a player, draw a card.

Thassa's Oracle

When Thassa's Oracle enters the battlefield, 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.)

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.

Thada Adel, Acquisitor

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that card.

Loyal Drake

Flying
Lieutenant — At the beginning of combat on your turn, if you control your commander, draw a card.

Teferi's Puzzle Box

At the beginning of each player's draw step, that player puts the cards in their hand on the bottom of their library in any order, then draws that many cards.

Fog Bank

Defender, flying
Prevent all combat damage that would be dealt to and dealt by Fog Bank.

Lighthouse Chronologist

Level up {U} ({U}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 4-6
2/4
LEVEL 7+
3/5
At the beginning of each end step, if it's not your turn, take an extra turn after this one.

Zahid, Djinn of the Lamp

You may pay {3}{U} and tap an untapped artifact you control rather than pay this spell's mana cost.
Flying

Scourge of Fleets

When Scourge of Fleets enters the battlefield, 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.

Reliquary Tower

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

Thought Vessel

Martyr of Frost

{2}, Reveal X blue cards from your hand, Sacrifice Martyr of Frost: Counter target spell unless its controller pays {X}.

Ghost Quarter

{T}: Add {C}.
{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."