Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Capsize

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Return target permanent to its owner's hand.

Aquitect's Will

Put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it. If you control a Merfolk, draw a card.

Sea's Claim

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

Vision Charm

Choose one —
• Target player mills four cards.
• Choose a land type and a basic land type. Each land of the first chosen type becomes the second chosen type until end of turn.
• Target artifact phases out. (While it's phased out, it's treated as though it doesn't exist. It phases in before its controller untaps during their next untap step.)

Unstable Mutation

Enchant creature
Enchanted creature gets +3/+3.
At the beginning of the upkeep of enchanted creature's controller, put a -1/-1 counter on that creature.

Déjà Vu

Return target sorcery card from your graveyard to your hand.

Flood

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

Flash Flood

Choose one —
• Destroy target red permanent.
• Return target Mountain to its owner's hand.

Tawnos's Wand

{2}, {T}: Target creature with power 2 or less can't be blocked this turn.

Vodalian Serpent

Kicker {2} (You may pay an additional {2} as you cast this spell.)
Vodalian Serpent can't attack unless defending player controls an Island.
If Vodalian Serpent was kicked, it enters with four +1/+1 counters on it.

Shimmering Mirage

Target land becomes the basic land type of your choice until end of turn.
Draw a card.

Spreading Seas

Enchant land
When Spreading Seas enters, draw a card.
Enchanted land is an Island.

Jinx

Target land becomes the basic land type of your choice until end of turn.
Draw a card at the beginning of the next turn's upkeep.

Sea Monster

Sea Monster can't attack unless defending player controls an Island.

Keep Watch

Reef Shaman

{T}: Target land becomes the basic land type of your choice until end of turn.

Port Inspector

Whenever Port Inspector becomes blocked, you may look at defending player's hand.

False Demise

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Phantasmal Terrain

Enchant land
As Phantasmal Terrain enters, choose a basic land type.
Enchanted land is the chosen type.

Steam Frigate

Steam Frigate can't attack unless defending player controls an Island.

Giant Albatross

Flying
When Giant Albatross dies, you may pay {1}{U}. If you do, for each creature that dealt damage to Giant Albatross this turn, destroy that creature unless its controller pays 2 life. A creature destroyed this way can't be regenerated.

Dark Maze

Defender (This creature can't attack.)
{0}: Dark Maze can attack this turn as though it didn't have defender. Exile it at the beginning of the next end step.

High Tide

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

Sift

Dream Thrush

Flying
{T}: Target land becomes the basic land type of your choice until end of turn.

Bay Falcon

Awesome Presence

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

Brilliant Plan

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.)

Mightstone

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Rishadan Cutpurse

When Rishadan Cutpurse enters, each opponent sacrifices a permanent of their choice unless they pay {1}.

Island

Reef Pirates

Whenever Reef Pirates deals damage to an opponent, that player mills a card.

Cloak of Invisibility

Enchant creature
Enchanted creature has phasing and can't be blocked except by Walls. (It phases in or out before its controller untaps during each of their untap steps. While it's phased out, it's treated as though it doesn't exist.)

Merchant Scroll

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

Clairvoyance

Look at target player's hand.
Draw a card at the beginning of the next turn's upkeep.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

Mana Leak

Counter target spell unless its controller pays {3}.

Diplomatic Immunity

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

Miscalculation

Counter target spell unless its controller pays {2}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Counterspell

Invisibility

Enchant creature
Enchanted creature can't be blocked except by Walls.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Mind Games

Buyback {2}{U} (You may pay an additional {2}{U} as you cast this spell. If you do, put this card into your hand as it resolves.)
Tap target artifact, creature, or land.

Intervene

Counter target spell that targets a creature.

Mystic Veil

You may cast Mystic Veil as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
Enchant creature
Enchanted creature has shroud. (It can't be the target of spells or abilities.)

Ghost Ship

Flash Counter

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Theft of Dreams

Dandân

Dandân can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Dandân.

Sunken City

At the beginning of your upkeep, sacrifice Sunken City unless you pay {U}{U}.
Blue creatures get +1/+1.

Red Cliffs Armada

Red Cliffs Armada can't attack unless defending player controls an Island.

Merfolk Looter

Tidal Warrior

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

Tidal Flats

{U}{U}: For each attacking creature without flying, its controller may pay {1}. If that player doesn't, creatures you control blocking that creature gain first strike until end of turn.

Giant Shark

Giant Shark can't attack unless defending player controls an Island.
Whenever Giant Shark blocks or becomes blocked by a creature that has been dealt damage this turn, Giant Shark gets +2/+0 and gains trample until end of turn.
When you control no Islands, sacrifice Giant Shark.

Merchant Ship

Merchant Ship can't attack unless defending player controls an Island.
Whenever Merchant Ship attacks and isn't blocked, you gain 2 life.
When you control no Islands, sacrifice Merchant Ship.

Mistfolk

{U}: Counter target spell that targets Mistfolk.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Betrayal

Enchant creature an opponent controls
Whenever enchanted creature becomes tapped, you draw a card.

Sea Serpent

Sea Serpent can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Sea Serpent.

Shadow Rift

Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)
Draw a card.