Desert of the Mindful

This land enters tapped.
{T}: Add {U}.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

Hornswoggle

Counter target creature spell. You create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Triton Shorestalker

Revolutionary Rebuff

Counter target nonartifact spell unless its controller pays {2}.

Island

Deeproot Waters

Whenever you cast a Merfolk spell, create a 1/1 blue Merfolk creature token with hexproof. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Prismwake Merrow

Flash
When this creature enters, target permanent becomes the color or colors of your choice until end of turn.

Headwater Sentries

Diviner's Wand

Equipped creature has "Whenever you draw a card, this creature gets +1/+1 and gains flying until end of turn" and "{4}: Draw a card."
Whenever a Wizard creature enters, you may attach this Equipment to it.
Equip {3}

Fallowsage

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

Reject

Counter target creature or planeswalker spell unless its controller pays {3}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Tide Shaper

Kicker {1} (You may pay an additional {1} as you cast this spell.)
When this creature enters, if it was kicked, target land becomes an Island for as long as this creature remains on the battlefield.
This creature gets +1/+1 as long as an opponent controls an Island.

Fountain of Ichor

{T}: Add one mana of any color.
{3}: This artifact becomes a 3/3 Dinosaur artifact creature until end of turn.

Triton Shorethief

Dazzling Lights

Target creature gets -3/-0 until end of turn.
Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Glimpse of Freedom

Draw a card.
Escape—{2}{U}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Paperfin Rascal

When this creature enters, clash with an opponent. If you win, put a +1/+1 counter on this creature. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Deeptread Merrow

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

Storm Sculptor

This creature can't be blocked.
When this creature enters, return a creature you control to its owner's hand.

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Vodalian Arcanist

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.

Coral Commando

River Darter

This creature can't be blocked by Dinosaurs.

Coralhelm Guide

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

Razorfin Abolisher

{1}{U}, {T}: Return target creature with a counter on it to its owner's hand.

Silvergill Adept

As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}.
When this creature enters, draw a card.

Ink Dissolver

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with this creature, you may reveal it. If you do, each opponent mills three cards.

No Escape

Counter target creature or planeswalker spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.
Scry 1.

Claustrophobia

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

Soothsayer Adept

{1}{U}, {T}: Draw a card, then discard a card.

Chilling Grasp

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.
Madness {3}{U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Salvager of Secrets

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Mental Journey

Draw three cards.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

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.

Traveler's Amulet

{1}, Sacrifice this artifact: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Raving Visionary

{U}, {T}: Draw a card, then discard a card.
Delirium — {2}{U}, {T}: Draw a card. Activate only if there are four or more card types among cards in your graveyard.

Test of Talents

Counter target instant or sorcery spell. Search its controller's graveyard, hand, and library for any number of cards with the same name as that spell and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Merfolk Sovereign

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

Convolute

Counter target spell unless its controller pays {4}.

Cancel

Riverwise Augur

When this creature enters, draw three cards, then put two cards from your hand on top of your library in any order.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Crashing Tide

This spell has flash as long as you control a Merfolk.
Return target creature to its owner's hand.
Draw a card.

Inkfathom Divers

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
When this creature enters, look at the top four cards of your library, then put them back in any order.

Maritime Guard

Silvergill Douser

{T}: Target creature gets -X/-0 until end of turn, where X is the number of Merfolk and/or Faeries you control.

Merrow Levitator

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

Coral Merfolk

Mist-Cloaked Herald

Didn't Say Please

Counter target spell. Its controller mills three cards.

Scour All Possibilities

Scry 2, then draw a card.
Flashback {4}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Memory Drain

Towering-Wave Mystic

Whenever this creature deals damage, target player mills that many cards.

Roilmage's Trick

Converge — Creatures your opponents control get -X/-0 until end of turn, where X is the number of colors of mana spent to cast this spell.
Draw a card.

Negate

Wilderness Hypnotist

{T}: Target red or green creature gets -2/-0 until end of turn.

Harbinger of the Tides

You may cast this card 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 this creature enters, you may return target tapped creature an opponent controls to its owner's hand.

Merrow Witsniper

When this creature enters, target player mills a card.

Rush of Ice

Tap target creature. It doesn't untap during its controller's next untap step.
Awaken 3—{4}{U} (If you cast this spell for {4}{U}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Tempest Caller

When this creature enters, tap all creatures target opponent controls.

Thought Collapse

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.

Seafloor Oracle

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

Spell Snuff

Counter target spell.
Fateful hour — If you have 5 or less life, draw a card.

Unexplained Disappearance

Return target creature to its owner's hand.
Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Dreadwaters

Target player mills X cards, where X is the number of lands you control.

Aquatic Incursion

When this enchantment enters, create two 1/1 blue Merfolk creature tokens with hexproof. (They can't be the targets of spells or abilities your opponents control.)
{3}{U}: Target Merfolk can't be blocked this turn.