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.

Forget

Target player discards two cards, then draws as many cards as they discarded this way.

Svyelunite Temple

This land enters tapped.
{T}: Add {U}.
{T}, Sacrifice this land: Add {U}{U}.

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.

Phantasmal Terrain

Enchant land
As this Aura enters, choose a basic land type.
Enchanted land is the chosen type.

Dance of the Dead

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Put enchanted creature card onto the battlefield tapped under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets +1/+1 and doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {1}{B}. If the player does, untap that creature.

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Lake of the Dead

If this land would enter, sacrifice a Swamp instead. If you do, put this land onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Swamp

Mana Vault

This artifact doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap this artifact.
At the beginning of your draw step, if this artifact is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Ghost Ship

Flying
{U}{U}{U}: Regenerate this creature.

Sea Serpent

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

Vodalian Mage

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

Sacrifice

As an additional cost to cast this spell, sacrifice a creature.
Add an amount of {B} equal to the sacrificed creature's mana value.

Deep Spawn

Trample
At the beginning of your upkeep, sacrifice this creature unless you mill two cards.
{U}: This creature gains shroud until end of turn and doesn't untap during your next untap step. Tap this creature. (A creature with shroud can't be the target of spells or abilities.)

Siren's Call

Cast this spell only during an opponent's turn, before attackers are declared.
Creatures the active player controls attack this turn if able.
At the beginning of the next end step, destroy all non-Wall creatures that player controls that didn't attack this turn. Ignore this effect for each creature the player didn't control continuously since the beginning of the turn.

Mystic Compass

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

Norritt

{T}: Untap target blue creature.
{T}: Choose target non-Wall creature the active player has controlled continuously since the beginning of the turn. That creature attacks this turn if able. Destroy it at the beginning of the next end step if it didn't attack this turn. Activate only before attackers are declared.

Mind Bomb

Each player may discard up to three cards. Mind Bomb deals damage to each player equal to 3 minus the number of cards they discarded this way.

Sol Ring

Leviathan

Trample
This creature enters tapped and doesn't untap during your untap step.
At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap this creature.
This creature can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Skeleton Ship

When you control no Islands, sacrifice Skeleton Ship.
{T}: Put a -1/-1 counter on target creature.

Unfulfilled Desires

{1}, Pay 1 life: Draw a card, then discard a card.

Krovikan Sorcerer

{T}, Discard a nonblack card: Draw a card.
{T}, Discard a black card: Draw two cards, then discard one of them.

Tangle Kelp

Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step if it attacked during its controller's last turn.

Animate Dead

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Soul Exchange

As an additional cost to cast this spell, exile a creature you control.
Return target creature card from your graveyard to the battlefield. Put a +2/+2 counter on that creature if the exiled creature was a Thrull.

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}.

Pirate Ship

This creature can't attack unless defending player controls an Island.
{T}: This creature deals 1 damage to any target.
When you control no Islands, sacrifice this creature.

Lord of Atlantis

Other Merfolk get +1/+1 and have islandwalk. (They can't be blocked as long as defending player controls an Island.)

Ebon Stronghold

This land enters tapped.
{T}: Add {B}.
{T}, Sacrifice this land: Add {B}{B}.

Storm Elemental

Flying
{U}, Exile the top card of your library: Tap target creature with flying.
{U}, Exile the top card of your library: If the exiled card is a snow land, this creature gets +1/+1 until end of turn.

Giant Shark

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

Sea Scryer

Illusionary Terrain

Cumulative upkeep {2} (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.)
As this enchantment enters, choose two basic land types.
Basic lands of the first chosen type are the second chosen type.

Kukemssa Serpent

This creature can't attack unless defending player controls an Island.
{U}, Sacrifice an Island: Target land an opponent controls becomes an Island until end of turn.
When you control no Islands, sacrifice this creature.

Lodestone Bauble

{1}, {T}, Sacrifice this artifact: Put up to four target basic land cards from a player's graveyard on top of their library in any order. That player draws a card at the beginning of the next turn's upkeep.

Control Magic

Enchant creature
You control enchanted creature.

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Vesuvan Doppelganger

You may have this creature enter as a copy of any creature on the battlefield, except it doesn't copy that creature's color and it has "At the beginning of your upkeep, you may have this creature become a copy of target creature, except it doesn't copy that creature's color and it has this ability."

Benthic Explorers

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

Benthic Djinn

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
At the beginning of your upkeep, you lose 2 life.

Ashes to Ashes

Exile two target nonartifact creatures. Ashes to Ashes deals 5 damage to you.

Charcoal Diamond

This artifact enters tapped.
{T}: Add {B}.

Dark Banishing

Destroy target nonblack creature. It can't be regenerated.

Copy Artifact

You may have this enchantment enter as a copy of any artifact on the battlefield, except it's an enchantment in addition to its other types.

Chain Stasis

You may tap or untap target creature. Then that creature's controller may pay {2}{U}. If the player does, they may copy this spell and may choose a new target for that copy.

Flood

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

Shallow Grave

Return the top creature card of your graveyard to the battlefield. That creature gains haste until end of turn. 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}.

Memory Lapse

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Floodgate

Defender
When this creature has flying, sacrifice it.
When this creature leaves the battlefield, it deals damage to each nonblue creature without flying equal to half the number of Islands you control, rounded down.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Vodalian Knights

First strike
This creature can't attack unless defending player controls an Island.
When you control no Islands, sacrifice this creature.
{U}: This creature gains flying until end of turn.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. This land deals 1 damage to you.

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Spiny Starfish

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

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.

Nevinyrral's Disk

This artifact enters tapped.
{1}, {T}: Destroy all artifacts, creatures, and enchantments.

Island

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.

Island Fish Jasconius

This creature doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {U}{U}{U}. If you do, untap this creature.
This creature can't attack unless defending player controls an Island.
When you control no Islands, sacrifice this creature.

Homarid Spawning Bed

{1}{U}{U}, Sacrifice a blue creature: Create X 1/1 blue Camarid creature tokens, where X is the sacrificed creature's mana value.

Underground Sea

Marjhan

This creature doesn't untap during your untap step.
{U}{U}, Sacrifice a creature: Untap this creature. Activate only during your upkeep.
This creature can't attack unless defending player controls an Island.
{U}{U}: This creature gets -1/-0 until end of turn and deals 1 damage to target attacking creature without flying.
When you control no Islands, sacrifice this creature.

Reef Pirates

Whenever this creature deals damage to an opponent, that player mills a card.

Polar Kraken

Trample
This creature enters tapped.
Cumulative upkeep—Sacrifice a land. (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.)

Basalt Monolith

This artifact doesn't untap during your untap step.
{T}: Add {C}{C}{C}.
{3}: Untap this artifact.

Sunken City

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