Seafloor Oracle

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

Lord of Atlantis

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

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

True-Name Nemesis

As True-Name Nemesis enters the battlefield, choose a player.
True-Name Nemesis has protection from the chosen player.

Spell Snare

Snapcaster Mage

Flash
When Snapcaster Mage enters the battlefield, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Engulf the Shore

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

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.

Vendilion Clique

Flash
Flying
When Vendilion Clique enters the battlefield, look at target player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.

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.)

Cosi's Trickster

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

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Daze

You may return an Island you control to its owner's hand rather than pay this spell's mana cost.
Counter target spell unless its controller pays {1}.

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.

Spreading Seas

Enchant land
When Spreading Seas enters the battlefield, draw a card.
Enchanted land is an Island.

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

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.

Metallic Mimic

As Metallic Mimic enters the battlefield, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters the battlefield with an additional +1/+1 counter on it.

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}

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

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.

Smuggler's Copter

Flying
Whenever Smuggler's Copter attacks or blocks, you may draw a card. If you do, discard a card.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Mana Leak

Counter target spell unless its controller pays {3}.

Jace, the Mind Sculptor

+2: Look at the top card of target player's library. You may put that card on the bottom of that player's library.
0: Draw three cards, then put two cards from your hand on top of your library in any order.
−1: Return target creature to its owner's hand.
−12: Exile all cards from target player's library, then that player shuffles their hand into their library.

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Island

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.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Counterspell

Cephalid Coliseum

{T}: Add {U}. Cephalid Coliseum deals 1 damage to you.
Threshold — {U}, {T}, Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

Venser, Shaper Savant

Flash
When Venser, Shaper Savant enters the battlefield, return target spell or permanent to its owner's hand.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Rishadan Port

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Merfolk Sovereign

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

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.

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Stifle

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Serum Visions

Radiant Fountain

When Radiant Fountain enters the battlefield, you gain 2 life.
{T}: Add {C}.

Remand

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard.
Draw a card.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

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.

Spell Pierce

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

Gush

You may return two Islands you control to their owner's hand rather than pay this spell's mana cost.
Draw two cards.

Blink of an Eye

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
Return target nonland permanent to its owner's hand. If this spell was kicked, draw a card.

Merfolk Trickster

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

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Mistcaller

Sacrifice Mistcaller: Until end of turn, if a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.

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.

Mutavault

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

Rootwater Thief

{U}: Rootwater Thief gains flying until end of turn.
Whenever Rootwater Thief deals combat damage to a player, you may pay {2}. If you do, search that player's library for a card and exile it, then the player shuffles.

Merrow Reejerey

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

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.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Mental Misstep

({U/P} can be paid with either {U} or 2 life.)
Counter target spell with mana value 1.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

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.

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Wasteland

{T}: Add {C}.
{T}, Sacrifice Wasteland: Destroy target nonbasic land.

Force Spike

Counter target spell unless its controller pays {1}.

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.

Vedalken Shackles

You may choose not to untap Vedalken Shackles during your untap step.
{2}, {T}: Gain control of target creature with power less than or equal to the number of Islands you control for as long as Vedalken Shackles remains tapped.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

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.)

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.")

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.

Cursecatcher

Sacrifice Cursecatcher: Counter target instant or sorcery spell unless its controller pays {1}.