Sleep Paralysis

Enchant creature
When Sleep Paralysis enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

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.

Mystic Sanctuary

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

Angler Drake

Flying
When Angler Drake enters the battlefield, you may return target creature to its owner's hand.

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Castle Vantress

Castle Vantress enters the battlefield tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Farfinder

Vigilance
When Farfinder enters the battlefield, you may search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Ulamog, the Ceaseless Hunger

When you cast this spell, exile two target permanents.
Indestructible
Whenever Ulamog, the Ceaseless Hunger attacks, defending player exiles the top twenty cards of their library.

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.

Warden of Geometries

Vigilance
{T}: Add {C}. ({C} represents colorless mana.)

Weapon Rack

Weapon Rack enters the battlefield with three +1/+1 counters on it.
{T}: Move a +1/+1 counter from Weapon Rack onto target creature. Activate only as a sorcery.

Thaumaturge's Familiar

Flying
When Thaumaturge's Familiar enters the battlefield, scry 1.

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}

Skyline Cascade

Skyline Cascade enters the battlefield tapped.
When Skyline Cascade enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.
{T}: Add {U}.

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."

Gift of Tusks

Until end of turn, target creature loses all abilities and becomes a green Elephant with base power and toughness 3/3.

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.

Cloudkin Seer

Flying
When Cloudkin Seer enters the battlefield, draw a card.

Heraldic Banner

As Heraldic Banner enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Unity of Purpose

Support 2. (Put a +1/+1 counter on each of up to two target creatures.)
Untap each creature you control with a +1/+1 counter on it.

Mirror Shield

Equipped creature gets +0/+2 and has hexproof and "Whenever a creature with deathtouch blocks or becomes blocked by this creature, destroy that creature."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Avian Oddity

Flying
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)
When you cycle Avian Oddity, put a flying counter on target creature you control.

Sage's Row Denizen

Whenever another blue creature enters the battlefield under your control, target player mills two cards.

Rise of Eagles

Create two 2/2 blue Bird enchantment creature tokens with flying. Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Nyx Lotus

Nyx Lotus enters the battlefield tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Mirrodin Besieged

As Mirrodin Besieged enters the battlefield, choose Mirran or Phyrexian.
• Mirran — Whenever you cast an artifact spell, create a 1/1 colorless Myr artifact creature token.
• Phyrexian — At the beginning of your end step, draw a card, then discard a card. Then if there are fifteen or more artifact cards in your graveyard, target opponent loses the game.

Prophet of the Peak

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

Island

Glimmerbell

Drawn from Dreams

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 a random order.

Sphere of the Suns

Sphere of the Suns enters the battlefield tapped and with three charge counters on it.
{T}, Remove a charge counter from Sphere of the Suns: Add one mana of any color.

Frost Lynx

When Frost Lynx enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Crashing Drawbridge

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

Overwhelming Denial

Surge {U}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
This spell can't be countered.
Counter target spell.

Faerie Vandal

Flash
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Mirrormade

You may have Mirrormade enter the battlefield as a copy of any artifact or enchantment on the battlefield.

Frost Titan

Whenever Frost Titan becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever Frost Titan enters the battlefield or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Corridor Monitor

When Corridor Monitor enters the battlefield, untap target artifact or creature you control.

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.

Masterful Replication

Choose one —
• Create two 3/3 colorless Golem artifact creature tokens.
• Choose target artifact you control. Each other artifact you control becomes a copy of that artifact until end of turn.

Scholar of the Ages

When Scholar of the Ages enters the battlefield, return up to two target instant and/or sorcery cards from your graveyard to your hand.

Moonlit Scavengers

When Moonlit Scavengers enters the battlefield, if you control an artifact or enchantment, return target creature an opponent controls to its owner's hand.

Reliquary Tower

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

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Overwhelmed Apprentice

When Overwhelmed Apprentice enters the battlefield, each opponent mills two cards. Then you scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

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.

Spectral Sailor

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

Incubator Drone

Devoid (This card has no color.)
When Incubator Drone enters the battlefield, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."

Bone to Ash

Counter target creature spell.
Draw a card.

Ichthyomorphosis

Enchant creature
Enchanted creature loses all abilities and is a blue Fish with base power and toughness 0/1.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters the battlefield with X +1/+1 counters on it.

Alloy Myr

Stolen by the Fae

Return target creature with mana value X to its owner's hand. You create X 1/1 blue Faerie creature tokens with flying.

Turn into a Pumpkin

Return target nonland permanent to its owner's hand. Draw a card.
Adamant — If at least three blue mana was spent to cast this spell, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Benthic Infiltrator

Devoid (This card has no color.)
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)
Benthic Infiltrator can't be blocked.

Enlightened Maniac

When Enlightened Maniac enters the battlefield, create a 3/2 colorless Eldrazi Horror creature token.

Diamond Mare

As Diamond Mare enters the battlefield, choose a color.
Whenever you cast a spell of the chosen color, you gain 1 life.

God-Pharaoh's Statue

Spells your opponents cast cost {2} more to cast.
At the beginning of your end step, each opponent loses 1 life.

Cyclone Sire

Flying
When Cyclone Sire dies, you may put three +1/+1 counters on target land you control. If you do, that land becomes a 0/0 Elemental creature with haste that's still a land.

Captivating Gyre

Return up to three target creatures to their owners' hands.

Tome Raider

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

Welcome to the Fold

Madness {X}{U}{U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
Gain control of target creature if its toughness is 2 or less. If this spell's madness cost was paid, instead gain control of that creature if its toughness is X or less.

Lunar Force

When an opponent casts a spell, sacrifice Lunar Force and counter that spell.

Riddlemaster Sphinx

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Riddlemaster Sphinx enters the battlefield, you may return target creature an opponent controls to its owner's hand.

Kiora's Dambreaker

When Kiora's Dambreaker enters the battlefield, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)