Coral Trickster

Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When Coral Trickster is turned face up, you may tap or untap target permanent.

Cleric of Chill Depths

Whenever Cleric of Chill Depths blocks a creature, that creature doesn't untap during its controller's next untap step.

Caller of Gales

{1}{U}, {T}: Target creature gains flying until end of turn.

Crush of Tentacles

Surge {3}{U}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Return all nonland permanents to their owners' hands. If this spell's surge cost was paid, create an 8/8 blue Octopus creature token.

Merrow Witsniper

When Merrow Witsniper enters the battlefield, target player mills a card.

Deepwater Hypnotist

Inspired — Whenever Deepwater Hypnotist becomes untapped, target creature an opponent controls gets -3/-0 until end of turn.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Brineborn Cutthroat.

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.

Skyline Cascade

Skyline Cascade enters the battlefield tapped.
When Skyline Cascade enters the battlefield, target creature an opponent controls doesn't untap during its controller's next untap step.
{T}: Add {U}.

Expedition Lookout

Defender
As long as an opponent has eight or more cards in their graveyard, Expedition Lookout can attack as though it didn't have defender and it can't be blocked.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

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.

Coralhelm Guide

{4}{U}: Target creature can't be blocked this turn.

Chain to Memory

Target creature gets -4/-0 until end of turn. Scry 2.

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.

Herald of Secret Streams

Creatures you control with +1/+1 counters on them can't be blocked.

Lord of Atlantis

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

Merrow Reejerey

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

Merrow Commerce

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

Merfolk Trickster

Flash
When Merfolk Trickster enters the battlefield, tap target creature an opponent controls. It loses all abilities until end of turn.

Dragon Turtle

Flash
Drag Below — When Dragon Turtle enters the battlefield, tap it and up to one target creature an opponent controls. They don't untap during their controllers' next untap steps.

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Shipwreck Dowser enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Augur of Bolas

When Augur of Bolas enters the battlefield, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Merrow Harbinger

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

Vodalian Hexcatcher

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

Merrow Levitator

{T}: Target creature gains flying until end of turn.
Whenever you cast a blue spell, you may untap Merrow Levitator.

Umara Entangler

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Fallowsage

Whenever Fallowsage becomes tapped, you may draw a card.

Door of Destinies

As Door of Destinies enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.

Deepchannel Mentor

Blue creatures you control can't be blocked.

Coralhelm Commander

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-3
3/3
Flying
LEVEL 4+
4/4
Flying
Other Merfolk creatures you control get +1/+1.

Dakra Mystic

{U}, {T}: Each player reveals the top card of their library. You may put the revealed cards into their owners' graveyards. If you don't, each player draws a card.

Arcane Signet

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

Gray Harbor Merfolk

Gray Harbor Merfolk can't be blocked.
Gray Harbor Merfolk gets +2/+0 as long as you control a commander that's a creature or planeswalker.

Cancel

Coral Commando

Wanderwine Prophets

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

Wake Thrasher

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

Headwater Sentries

Stonybrook Angler

{1}{U}, {T}: You may tap or untap target creature.

Frostwind Invoker

Flying
{8}: Creatures you control gain flying until end of turn.

Bone to Ash

Counter target creature spell.
Draw a card.

Sol Ring

Protective Bubble

Enchant creature
Enchanted creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)

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.)

Coral Fighters

Whenever Coral Fighters attacks and isn't blocked, look at the top card of defending player's library. You may put that card on the bottom of that player's library.

River Sneak

River Sneak can't be blocked.
Whenever another Merfolk enters the battlefield under your control, River Sneak gets +1/+1 until end of turn.

Cosi's Trickster

Whenever an opponent shuffles their library, you may put a +1/+1 counter on Cosi's Trickster.

Benthic Biomancer

{1}{U}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on Benthic Biomancer, draw a card, then discard a card.

Octopus Umbra

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Merrow Wavebreakers

{1}{U}, {Q}: Merrow Wavebreakers gains flying until end of turn. ({Q} is the untap symbol.)

Merfolk Sovereign

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

Glimmerpost

When Glimmerpost enters the battlefield, you gain 1 life for each Locus on the battlefield.
{T}: Add {C}.

Harbinger of the Tides

You may cast Harbinger of the Tides as though it had flash if you pay {2} more to cast it. (You may cast it any time you could cast an instant.)
When Harbinger of the Tides enters the battlefield, you may return target tapped creature an opponent controls to its owner's hand.

Deeptread Merrow

{U}: Deeptread Merrow gains islandwalk until end of turn. (It can't be blocked as long as defending player controls an Island.)

Merfolk Thaumaturgist

{T}: Switch target creature's power and toughness until end of turn.

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.

Behold the Multiverse

Scry 2, then draw two cards.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Prismwake Merrow

Flash
When Prismwake Merrow enters the battlefield, target permanent becomes the color or colors of your choice until end of turn.

Admiral's Order

Raid — If you attacked this turn, you may pay {U} rather than pay this spell's mana cost.
Counter target spell.