Cephalid Retainer

{U}{U}: Tap target creature without flying.

Psychic Trance

Until end of turn, Wizards you control gain "{T}: Counter target spell."

Wash Out

Return all permanents of the color of your choice to their owners' hands.

Crystal Spray

Change the text of target spell or permanent by replacing all instances of one color word with another or one basic land type with another until end of turn.
Draw a card.

Cephalid Broker

{T}: Target player draws two cards, then discards two cards.

Cephalid Illusionist

Whenever Cephalid Illusionist becomes the target of a spell or ability, mill three cards.
{2}{U}, {T}: Prevent all combat damage that would be dealt to and dealt by target creature you control this turn.

Sol Ring

Control Magic

Enchant creature
You control enchanted creature.

Painter's Servant

As Painter's Servant enters the battlefield, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Cephalid Scout

Flying
{2}{U}, Sacrifice a land: Draw a card.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Paralyzing Grasp

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.

Whelming Wave

Return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.

Churning Eddy

Return target creature and target land to their owners' hands.

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.

Sand Squid

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
You may choose not to untap Sand Squid during your untap step.
{T}: Tap target creature. That creature doesn't untap during its controller's untap step for as long as Sand Squid remains tapped.

Keep Watch

Plagiarize

Until end of turn, if target player would draw a card, instead that player skips that draw and you draw a card.

Sleight of Mind

Change the text of target spell or permanent by replacing all instances of one color word with another. (For example, you may change "target black spell" to "target blue spell." This effect lasts indefinitely.)

Vodalian Mage

{U}, {T}: Counter target spell unless its controller pays {1}.

Sea Kings' Blessing

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

Gulf Squid

When Gulf Squid enters the battlefield, tap all lands target player controls.

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}.

Touch of Invisibility

Target creature can't be blocked this turn.
Draw a card.

Boomerang

Return target permanent to its owner's hand.

Tidal Warrior

{T}: Target land becomes an Island until end of turn.

Chameleon Spirit

As Chameleon Spirit enters the battlefield, choose a color.
Chameleon Spirit's power and toughness are each equal to the number of permanents of the chosen color your opponents control.

Artificial Evolution

Change the text of target spell or permanent by replacing all instances of one creature type with another. The new creature type can't be Wall. (This effect lasts indefinitely.)

Primal Plasma

As Primal Plasma enters the battlefield, it becomes your choice of a 3/3 creature, a 2/2 creature with flying, or a 1/6 creature with defender.

Streambed Aquitects

{T}: Target Merfolk creature gets +1/+1 and gains islandwalk until end of turn. (It can't be blocked as long as defending player controls an Island.)
{T}: Target land becomes an Island until end of turn.

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.

Fylamarid

Flying
Fylamarid can't be blocked by blue creatures.
{U}: Target creature becomes blue until end of turn.

Windrider Eel

Flying
Landfall — Whenever a land enters the battlefield under your control, Windrider Eel gets +2/+2 until end of turn.

Shifting Sky

As Shifting Sky enters the battlefield, choose a color.
All nonland permanents are the chosen color.

Temporal Cascade

Choose one —
• Each player shuffles their hand and graveyard into their library.
• Each player draws seven cards.
Entwine {2} (Choose both if you pay the entwine cost.)

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.

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.

Island

Void Snare

Return target nonland permanent to its owner's hand.

TAKE OUT

Spellbook

Callous Oppressor

You may choose not to untap Callous Oppressor during your untap step.
As Callous Oppressor enters the battlefield, an opponent chooses a creature type.
{T}: Gain control of target creature that isn't of the chosen type for as long as Callous Oppressor remains tapped.

Mind Bend

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Sea's Claim

Enchant land (Target a land as you cast this. This card enters the battlefield attached to that land.)
Enchanted land is an Island.

Fervent Denial

Counter target spell.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Cryptoplasm

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

Godhunter Octopus

Godhunter Octopus can't attack unless defending player controls an enchantment or an enchanted permanent.

Psionic Gift

Enchant creature
Enchanted creature has "{T}: This creature deals 1 damage to any target."

Immobilizing Ink

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Enchanted creature has "{1}, Discard a card: Untap this creature."

Awesome Presence

Enchant creature
Enchanted creature can't be blocked unless defending player pays {3} for each creature they control that's blocking it.

Aquamorph Entity

As Aquamorph Entity enters the battlefield or is turned face up, it becomes your choice of 5/1 or 1/5.
Morph {2}{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.)

Aboshan, Cephalid Emperor

Tap an untapped Cephalid you control: Tap target permanent.
{U}{U}{U}: Tap all creatures without flying.

Chill

The Reality Chip

You may look at the top card of your library any time.
As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library.
Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

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.)

Benthic Explorers

{T}, Untap a tapped land an opponent controls: Add one mana of any type that land could produce.

Wall of Wonder

Defender (This creature can't attack.)
{2}{U}{U}: Wall of Wonder gets +4/-4 until end of turn and can attack this turn as though it didn't have defender.

Cephalid Sage

Threshold — As long as seven or more cards are in your graveyard, Cephalid Sage has "When Cephalid Sage enters the battlefield, draw three cards, then discard two cards."

Viscerid Armor

Enchant creature
Enchanted creature gets +1/+1.
{1}{U}: Return Viscerid Armor to its owner's hand.

Think Tank

At the beginning of your upkeep, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Cephalid Inkshrouder

Discard a card: Cephalid Inkshrouder gains shroud until end of turn and can't be blocked this turn. (A creature with shroud can't be the target of spells or abilities.)

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Cephalid Looter

{T}: Target player draws a card, then discards a card.

Renegade Doppelganger

Whenever another creature enters the battlefield under your control, you may have Renegade Doppelganger become a copy of that creature until end of turn. (If it does, it loses this ability for the rest of the turn.)

Kraken Hatchling

Stonybrook Banneret

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Merfolk spells and Wizard spells you cast cost {1} less to cast.

Unsummon

Return target creature to its owner's hand.

Dragon Wings

Enchant creature
Enchanted creature has flying.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When a creature with mana value 6 or greater enters the battlefield, you may return Dragon Wings from your graveyard to the battlefield attached to that creature.

Backfire

Enchant creature
Whenever enchanted creature deals damage to you, Backfire deals that much damage to that creature's controller.

Windfall

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

Sapphire Medallion

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

Back to Basics

Nonbasic lands don't untap during their controllers' untap steps.

Whim of Volrath

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another until end of turn. (For example, you may change "nonred creature" to "nongreen creature" or "plainswalk" to "swampwalk.")

Sway of Illusion

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

Wilderness Hypnotist

{T}: Target red or green creature gets -2/-0 until end of turn.

Spiny Starfish

{U}: Regenerate Spiny Starfish.
At the beginning of each end step, if Spiny Starfish regenerated this turn, create a 0/1 blue Starfish creature token for each time it regenerated this turn.