Merrow Harbinger

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
When this creature enters, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

Sea of Clouds

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Eclipsed Merrow

When this creature enters, look at the top four cards of your library. You may reveal a Merfolk, Plains, or Island card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Vodalian Hexcatcher

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

Fountainport

{T}: Add {C}.
{2}, {T}, Sacrifice a token: Draw a card.
{3}, {T}, Pay 1 life: Create a 1/1 blue Fish creature token.
{4}, {T}: Create a Treasure token.

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.

Zephyr Singer

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
When this creature enters, put a flying counter on each creature that convoked it.

Jori En, Ruin Diver

Whenever you cast your second spell each turn, draw a card.

Plains

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Mindspring Merfolk

Exhaust — {X}{U}{U}, {T}: Draw X cards. Put a +1/+1 counter on each Merfolk creature you control. (Activate each exhaust ability only once.)

Meeting of Minds

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw two cards.

Raise the Past

Return all creature cards with mana value 2 or less from your graveyard to the battlefield.

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}.)

Tishana's Tidebinder

Flash
When this creature enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as this creature remains on the battlefield. (Mana abilities can't be targeted.)

Deepway Navigator

Flash
When this creature enters, untap each other Merfolk you control.
As long as you attacked with three or more Merfolk this turn, Merfolk you control get +1/+0.

Arcane Signet

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

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Judge of Currents

Whenever a Merfolk you control becomes tapped, you may gain 1 life.

Deepchannel Duelist

At the beginning of your end step, untap target Merfolk you control.
Other Merfolk you control get +1/+1.

Sygg's Command

Choose two —
• Create a token that's a copy of target Merfolk you control.
• Creatures target player controls gain lifelink until end of turn.
• Target player draws a card.
• Tap target creature. Put a stun counter on it.

Pestered Wellguard

Whenever this creature becomes tapped, create a 1/1 blue and black Faerie creature token with flying.

Forensic Researcher

{T}: Untap another target permanent you control.
{T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Don't Have

Wand of the Worldsoul

This artifact enters tapped.
{T}: Add {W}.
{T}: The next spell you cast this turn has convoke.

Clever Concealment

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Any number of target nonland permanents you control phase out. (Treat them and anything attached to them as though they don't exist until your next turn.)

Sol Ring

Sunbillow Verge

{T}: Add {W}.
{T}: Add {R}. Activate only if you control a Mountain or a Plains.

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Tidal Warrior

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

Hallowed Fountain

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

Unexpected Assistance

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw three cards, then discard a card.

Summon the School

Create two 1/1 blue Merfolk Wizard creature tokens.
Tap four untapped Merfolk you control: Return this card from your graveyard to your hand.

Caetus, Sea Tyrant of Segovia

Noncreature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
At the beginning of your end step, untap up to four target creatures.

Invasion of Segovia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, create two 1/1 blue Kraken creature tokens with trample.

Invasion of Segovia // Caetus, Sea Tyrant of Segovia

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

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.

Lofty Dreams

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Enchant creature
When this Aura enters, draw a card.
Enchanted creature gets +2/+2 and has flying.

Jeskai Ascendancy

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.
Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

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.

Merrow Skyswimmer

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
When this creature enters, create a 1/1 white and blue Merfolk creature token.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Protective Response

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy target attacking or blocking creature.

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Training Center

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Fallowsage

Whenever this creature becomes tapped, you may draw a card.

The Jolly Balloon Man

Haste
{1}, {T}: Create a token that's a copy of another target creature you control, except it's a 1/1 red Balloon creature in addition to its other colors and types and it has flying and haste. Sacrifice it at the beginning of the next end step. Activate only as a sorcery.

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.

Sea Scryer

Emperor Mihail II

You may look at the top card of your library any time.
You may cast Merfolk spells from the top of your library.
Whenever you cast a Merfolk spell, you may pay {1}. If you do, create a 1/1 blue Merfolk creature token.

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.

Wanderbrine Trapper

{1}, {T}, Tap another untapped creature you control: Tap target creature an opponent controls.

Flockchaser Phantom

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance
Whenever this creature attacks, the next spell you cast this turn has convoke.

Cut Short

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy target planeswalker that was activated this turn or tapped creature.

Mountain

Omni-Changeling

Changeling (This card is every creature type.)
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
You may have this creature enter as a copy of any creature on the battlefield, except it has changeling.

Expedition Diviner

Flying
As long as you control another Wizard, this creature has "When this creature dies, draw a card."

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.

Exotic Orchard

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

Puresight Merrow

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

Talisman of Progress

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

Kasla, the Broken Halo

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Flying, vigilance, haste
Whenever you cast another spell that has convoke, scry 2, then draw a card.

Seafloor Oracle

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

The Wandering Rescuer

Flash
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Double strike
Other tapped creatures you control have hexproof.

Deeproot Pilgrimage

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Tideshaper Mystic

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

Silvergill Mentor

As an additional cost to cast this spell, behold a Merfolk or pay {2}. (To behold a Merfolk, choose a Merfolk you control or reveal a Merfolk from your hand.)
When this creature enters, create a 1/1 white and blue Merfolk creature token.

Collective Inferno

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As this enchantment enters, choose a creature type.
Double all damage that sources you control of the chosen type would deal.

Adept Watershaper

Other tapped creatures you control have indestructible.

Silvergill Peddler

Whenever this creature becomes tapped, draw a card, then discard a card.

Winnowing

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
For each player, you choose a creature that player controls. Then each player sacrifices all other creatures they control that don't share a creature type with the chosen creature they control.

Sygg, Wanderbrine Shield

Sygg can't be blocked.
Whenever this creature transforms into Sygg, Wanderbrine Shield, target creature you control gains protection from each color until your next turn.
At the beginning of your first main phase, you may pay {U}. If you do, transform Sygg.

Sygg, Wanderwine Wisdom

Sygg can't be blocked.
Whenever this creature enters or transforms into Sygg, Wanderwine Wisdom, target creature gains "Whenever this creature deals combat damage to a player or planeswalker, draw a card" until end of turn.
At the beginning of your first main phase, you may pay {W}. If you do, transform Sygg.

Sygg, Wanderwine Wisdom // Sygg, Wanderbrine Shield

Kindred Charge

Choose a creature type. For each creature you control of the chosen type, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Splinter Twin

Enchant creature
Enchanted creature has "{T}: Create a token that's a copy of this creature, except it has haste. Exile that token at the beginning of the next end step."

Knight-Errant of Eos

Convoke
When this creature enters, look at the top six cards of your library. You may reveal up to two creature cards with mana value X or less from among them, where X is the number of creatures that convoked this creature. Put the revealed cards into your hand, then shuffle.

Lullmage Mentor

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token.
Tap seven untapped Merfolk you control: Counter target spell.

Sacred Foundry

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

Bennie Bracks, Zoologist

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
At the beginning of each end step, if you created a token this turn, draw a card.

Shared Animosity

Whenever a creature you control attacks, it gets +1/+0 until end of turn for each other attacking creature that shares a creature type with it.

Steam Vents

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

Sigil Tracer

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

Chant of Vitu-Ghazi

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Prevent all damage that would be dealt by creatures this turn. You gain life equal to the damage prevented this way.

Harmonized Crescendo

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose a creature type. Draw a card for each permanent you control of that type.

Whirlpool Warrior

When this creature enters, shuffle the cards from your hand into your library, then draw that many cards.
{R}, Sacrifice this creature: Each player shuffles the cards from their hand into their library, then draws that many cards.

Deepchannel Mentor

Blue creatures you control can't be blocked.

Stonybrook Schoolmaster

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

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Island

Merrow Commerce

At the beginning of your end step, untap all Merfolk you control.

Meanders Guide

Whenever this creature attacks, you may tap another untapped Merfolk you control. When you do, return target creature card with mana value 3 or less from your graveyard to the battlefield.

Riverpyre Verge

{T}: Add {R}.
{T}: Add {U}. Activate only if you control an Island or a Mountain.

Everything Comes to Dust

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Exile all creatures except those that share a creature type with a creature that convoked this spell, all artifacts, and all enchantments.

Command Tower

Vodalian Wave-Knight

Whenever you draw a card, put a +1/+1 counter on each other Merfolk and/or Knight you control.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Swords to Plowshares

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

Raugrin Triome

({T}: Add {U}, {R}, or {W}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Split Up

Choose one —
• Destroy all tapped creatures.
• Destroy all untapped creatures.

Fellwar Stone

Calamity of Cinders

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Calamity of Cinders deals 6 damage to each untapped creature.

Reflection of Kiki-Jiki

{1}, {T}: Create a token that's a copy of another target nonlegendary creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Fable of the Mirror-Breaker

(As this Saga enters and after your draw step, add a lore counter.)
I — Create a 2/2 red Goblin Shaman creature token with "Whenever this token attacks, create a Treasure token."
II — You may discard up to two cards. If you do, draw that many cards.
III — Exile this Saga, then return it to the battlefield transformed under your control.