Sigil Tracer

{1}{U}, Tap two untapped Wizards you control: Copy target instant or sorcery spell. You may choose new targets for the copy.

Kabira Plateau

Kabira Takedown

Kabira Takedown deals damage equal to the number of creatures you control to target creature or planeswalker.

Kabira Takedown // Kabira Plateau

Riptide Shapeshifter

{2}{U}{U}, Sacrifice this creature: Choose a creature type. Reveal cards from the top of your library until you reveal a creature card of that type. Put that card onto the battlefield and shuffle the rest into your library.

Master of the Pearl Trident

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

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.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

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.

Sea Gate, Reborn

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sea Gate Restoration

Draw cards equal to the number of cards in your hand plus one. You have no maximum hand size for the rest of the game.

Sea Gate Restoration // Sea Gate, Reborn

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Phantasmal Image

You may have this creature enter as a copy of any creature on the battlefield, except it's an Illusion in addition to its other types and it has "When this creature becomes the target of a spell or ability, sacrifice it."

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Fierce Guardianship

If you control a commander, you may cast this spell without paying its mana cost.
Counter target noncreature spell.

Empress Galina

{U}{U}, {T}: Gain control of target legendary permanent. (This effect lasts indefinitely.)

Kopala, Warden of Waves

Spells your opponents cast that target a Merfolk you control cost {2} more to cast.
Abilities your opponents activate that target a Merfolk you control cost {2} more to activate.

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.

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.

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}.

Beyeen Coast

Beyeen Veil

Creatures your opponents control get -2/-0 until end of turn.

Beyeen Veil // Beyeen Coast

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Seafloor Oracle

Whenever a Merfolk you control deals combat damage to a player, draw a card.

Prismatic Vista

{T}, Pay 1 life, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Surgespanner

Whenever this creature becomes tapped, you may pay {1}{U}. If you do, return target permanent to its owner's hand.

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.

Sol Ring

Misty Rainforest

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Scalding Tarn

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Tundra

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Spellskite

{U/P}: Change a target of target spell or ability to this creature. ({U/P} can be paid with either {U} or 2 life.)

Wanderwine Prophets

Champion a Merfolk (When this enters, sacrifice it unless you exile another Merfolk you control. When this leaves the battlefield, that card returns to the battlefield.)
Whenever this creature deals combat damage to a player, you may sacrifice a Merfolk. If you do, take an extra turn after this one.

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard this card: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Plaza of Heroes

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.
{T}: Add one mana of any color among legendary permanents you control.
{3}, {T}, Exile this land: Target legendary creature gains hexproof and indestructible until end of turn.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Trickbind

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Counter target activated or triggered ability. If a permanent's ability is countered this way, activated abilities of that permanent can't be activated this turn. (Mana abilities can't be targeted.)

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Basalt Monolith

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

Flagstones of Trokair

{T}: Add {W}.
When Flagstones of Trokair is put into a graveyard from the battlefield, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Counterspell

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Wake Thrasher

Whenever a permanent you control becomes untapped, this creature gets +1/+1 until end of turn.

Glasspool Shore

Glasspool Mimic

You may have this creature enter as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Mimic // Glasspool Shore

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

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.")

Stonybrook Schoolmaster

Whenever this creature becomes tapped, you may create a 1/1 blue Merfolk Wizard creature token.

Umezawa's Jitte

Whenever equipped creature deals combat damage, put two charge counters on Umezawa's Jitte.
Remove a charge counter from Umezawa's Jitte: Choose one —
• Equipped creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.
Equip {2}

Mutavault

{T}: Add {C}.
{1}: This land becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Seahunter

{3}, {T}: Search your library for a Merfolk permanent card, put it onto the battlefield, then shuffle.

Arcane Signet

Plains

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have this creature enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Cavern of Souls

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

City of Brass

Whenever this land becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Kindred Discovery

As this enchantment enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Tideshaper Mystic

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

Ancient Tomb

{T}: Add {C}{C}. This land deals 2 damage to you.

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard this card: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Puresight Merrow

{W/U}, {Q}: Look at the top card of your library. You may exile that card. ({Q} is the untap symbol.)

Lord of Atlantis

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

Island

Avacyn, Angel of Hope

Flying, vigilance, indestructible
Other permanents you control have indestructible.

Merfolk Sovereign

Other Merfolk creatures you control get +1/+1.
{T}: Target Merfolk creature can't be blocked this turn.

Reef Shaman

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

Opposition

Tap an untapped creature you control: Tap target artifact, creature, or land.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

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.

Thassa's Oracle

When this creature enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice this land: You may cast spells this turn as though they had flash.

Solitude

Flash
Lifelink
When this creature enters, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Wanderwine Hub

As this land enters, you may reveal a Merfolk card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {U}.

Gilded Drake

Flying
When this creature enters, exchange control of this creature and up to one target creature an opponent controls. If you don't or can't make an exchange, sacrifice this creature. This ability still resolves if its target becomes illegal.

Petrified Field

{T}: Add {C}.
{T}, Sacrifice this land: Return target land card from your graveyard to your hand.

Svyelun of Sea and Sky

Svyelun has indestructible as long as you control at least two other Merfolk.
Whenever Svyelun attacks, draw a card.
Other Merfolk you control have ward {1}. (Whenever another Merfolk you control becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

Vodalian Hexcatcher

Flash
Other Merfolk you control get +1/+1.
Sacrifice a Merfolk: Counter target noncreature spell unless its controller pays {1}.

Sygg, River Guide

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{1}{W}: Target Merfolk you control gains protection from the color of your choice until end of turn.

Arid Mesa

{T}, Pay 1 life, Sacrifice this land: Search your library for a Mountain or Plains card, put it onto the battlefield, then shuffle.

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.

Seasinger

When you control no Islands, sacrifice this creature.
You may choose not to untap this creature during your untap step.
{T}: Gain control of target creature whose controller controls an Island for as long as you control this creature and this creature remains tapped.

Merrow Reejerey

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Azorius Signet

Eiganjo Castle

{T}: Add {W}.
{W}, {T}: Prevent the next 2 damage that would be dealt to target legendary creature this turn.

Merfolk Trickster

Flash
When this creature enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Spreading Seas

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

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {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.)