Have

Tidal Barracuda

Any player may cast spells as though they had flash.
Your opponents can't cast spells during your turn.

Getting

Sapphire Medallion

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

Vodalian Mage

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

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.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Boomerang

Return target permanent to its owner's hand.

Harbinger of the Seas

Don't Have

Void Snare

Return target nonland permanent to its owner's hand.

Chill

Aboshan, Cephalid Emperor

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

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Back to Basics

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

Backfire

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

Sway of Illusion

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

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Shifting Sky

As this enchantment enters, choose a color.
All nonland permanents are the chosen color.

Keep Watch

Sol Ring

Venser's Journal

You have no maximum hand size.
At the beginning of your upkeep, you gain 1 life for each card in your hand.

Wonder

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

Cephalid Sage

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

Soul Barrier

Whenever an opponent casts a creature spell, this enchantment deals 2 damage to that player unless they pay {2}.

Mystic Sanctuary

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

Counterspell

Control Magic

Enchant creature
You control enchanted creature.

Merchant Scroll

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

Psychic Trance

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

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.

Gulf Squid

When this creature enters, tap all lands target player controls.

Churning Eddy

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

Walking Sponge

{T}: Target creature loses your choice of flying, first strike, or trample until end of turn.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Llawan, Cephalid Empress

When Llawan enters, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Engulf the Shore

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

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Cephalid Illusionist

Whenever this creature 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.

Mana Breach

Whenever a player casts a spell, that player returns a land they control to its owner's hand.

Cryptoplasm

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

Tidal Warrior

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

Sea Kings' Blessing

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

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.)

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.)

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.")

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, you may return this card from your graveyard to the battlefield attached to that creature.

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.)

Terramorphic Expanse

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

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.)

Wash Out

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

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Paragon of Gathering Mists

Other blue creatures you control get +1/+1.
{U}, {T}: Another target blue creature you control gains flying until end of turn.

Painter's Servant

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

Evolving Wilds

True-Name Nemesis

As this creature enters, choose a player.
This creature has protection from the chosen player.

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.")

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.)

Giant Oyster

You may choose not to untap this creature during your untap step.
{T}: For as long as this creature remains tapped, target tapped creature doesn't untap during its controller's untap step, and at the beginning of each of your draw steps, put a -1/-1 counter on that creature. When this creature leaves the battlefield or becomes untapped, remove all -1/-1 counters from the creature.

Whelming Wave

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

Nyx Lotus

Nyx Lotus enters 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.)

Curse of Verbosity

Enchant player
Whenever enchanted player is attacked, you draw a card. Each opponent attacking that player does the same.

Paralyzing Grasp

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

High Tide

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

Island

Callous Oppressor

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

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Plagiarize

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

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.

Energy Flux

All artifacts have "At the beginning of your upkeep, sacrifice this artifact unless you pay {2}."

Windfall

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

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.

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."

Sand Squid

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

Cephalid Retainer

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

Spreading Seas

Enchant land
When this Aura enters, draw a card.
Enchanted land is an Island.

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.