Vodalian Mage

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

Windrider Patrol

Flying
Whenever Windrider Patrol deals combat damage to a player, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Into the Void

Return up to two target creatures to their owners' hands.

Arcane Signet

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

Svyelun of Sea and Sky

Svyelun of Sea and Sky 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}.)

Reservoir Kraken

Trample, ward {2}
At the beginning of each combat, if Reservoir Kraken is untapped, any opponent may tap an untapped creature they control. If they do, tap Reservoir Kraken and create a 1/1 blue Fish creature token with "This creature can't be blocked."

Deepchannel Mentor

Blue creatures you control can't be blocked.

Paralyzing Grasp

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.

Tidebinder Mage

When Tidebinder Mage enters the battlefield, tap target red or green creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Tidebinder Mage.

In Bolas's Clutches

Enchant permanent
You control enchanted permanent.
Enchanted permanent is legendary.

Legacy's Allure

At the beginning of your upkeep, you may put a treasure counter on Legacy's Allure.
Sacrifice Legacy's Allure: Gain control of target creature with power less than or equal to the number of treasure counters on Legacy's Allure. (This effect lasts indefinitely.)

Inevitable Betrayal

Suspend 3—{1}{U}{U} (Rather than cast this card from your hand, pay {1}{U}{U} and exile it with three time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Dispel

Triton Shorestalker

Vow of Flight

Enchant creature
Enchanted creature gets +2/+2, has flying, and can't attack you or planeswalkers you control.

Tide Shaper

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

Open into Wonder

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

Press for Answers

Tap target creature. It doesn't untap during its controller's next untap step.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Tempest Djinn

Flying
Tempest Djinn gets +1/+0 for each basic Island you control.

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.

Staff of the Mind Magus

Whenever you cast a blue spell or an Island enters the battlefield under your control, you gain 1 life.

Merfolk of the Pearl Trident

Tazeem Roilmage

Kicker {4} (You may pay an additional {4} as you cast this spell.)
When Tazeem Roilmage enters the battlefield, if it was kicked, return target instant or sorcery card from your graveyard to your hand.

Soulsworn Spirit

Soulsworn Spirit can't be blocked.
When Soulsworn Spirit enters the battlefield, detain target creature an opponent controls. (Until your next turn, that creature can't attack or block and its activated abilities can't be activated.)

Negate

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}

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.

Rescind

Return target permanent to its owner's hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

Aquatic Incursion

When Aquatic Incursion enters the battlefield, 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.

Seafloor Oracle

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

Witness Protection

Enchant creature
Enchanted creature loses all abilities and is a green and white Citizen creature with base power and toughness 1/1 named Legitimate Businessperson. (It loses all other colors, card types, creature types, and names.)

Bone to Ash

Counter target creature spell.
Draw a card.

Web of Inertia

At the beginning of combat on each opponent's turn, that player may exile a card from their graveyard. If the player doesn't, creatures they control can't attack you this turn.

Mahamoti Djinn

Flying (This creature can't be blocked except by creatures with flying or reach.)

Silvergill Douser

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

Merfolk Traders

When Merfolk Traders enters the battlefield, draw a card, then discard a card.

Mass Manipulation

Gain control of X target creatures and/or planeswalkers.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Merfolk Windrobber

Flying
Whenever Merfolk Windrobber deals combat damage to a player, that player mills a card. (They put the top card of their library into their graveyard.)
Sacrifice Merfolk Windrobber: Draw a card. Activate only if an opponent has eight or more cards in their graveyard.

Merfolk Sovereign

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

Cleric of Chill Depths

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

Island

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Kasmina's Transmutation

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

Psychic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you scry 2.

Wilderness Hypnotist

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

Reach Through Mists

Master Thief

When Master Thief enters the battlefield, gain control of target artifact for as long as you control Master Thief.

Hibernation

Return all green permanents to their owners' hands.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Watertrap Weaver

When Watertrap Weaver enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Essence Scatter

Hidden Strings

You may tap or untap target permanent, then you may tap or untap another target permanent.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Crashing Tide

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

Merrow Reejerey

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

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.

Void Snare

Return target nonland permanent 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 Silvergill Adept enters the battlefield, draw a card.

Urza's Rebuff

Choose one —
• Counter target spell.
• Tap up to two target creatures.

Exclude

Silver Scrutiny

You may cast Silver Scrutiny as though it had flash if X is 3 or less.
Draw X cards.

Vodalian Arcanist

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

Bitter Chill

Enchant creature
When Bitter Chill enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
When Bitter Chill is put into a graveyard from the battlefield, you may pay {1}. If you do, scry 1, then draw a card.

You See a Guard Approach

Choose one —
• Distract the Guard — Tap target creature.
• Hide — Target creature you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)