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.
2 /
1
{1}{U}{U}
Cancel
Instant
Counter target spell.
{1}{U}{U}
Cancel
Instant
Counter target spell.
{1}{U}
Chart a Course
Sorcery
Draw two cards. Then discard a card unless you attacked this turn.
{3}{U}
Choking Tethers
Instant
Tap up to four target creatures.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Choking Tethers, you may tap target creature.
{2}{G}
Courage in Crisis
Sorcery
Put a +1/+1 counter on target creature, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
{2}{U}
Crashing Tide
Sorcery
This spell has flash as long as you control a Merfolk.
Return target creature to its owner's hand.
Draw a card.
{1}{U}
Deepwater Hypnotist
Creature - Merfolk Wizard
Inspired -- Whenever Deepwater Hypnotist becomes untapped, target creature an opponent controls gets -3/-0 until end of turn.
2 /
1
{2}
Demon's Horn
Artifact
Whenever a player casts a black spell, you may gain 1 life.
{3}{U}
Disorient
Instant
Target creature gets -7/-0 until end of turn.
{3}{G}
Dragonscale Boon
Instant
Put two +1/+1 counters on target creature and untap it.
{2}{U}
Dream Cache
Sorcery
Draw three cards, then put two cards from your hand both on top of your library or both on the bottom of your library.
{1}{U}
Early Frost
Instant
Tap up to three target lands.
{2}{U}
Enclave Elite
Creature - Merfolk Soldier
Multikicker {1}{U} (You may pay an additional {1}{U} any number of times as you cast this spell.)
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Enclave Elite enters the battlefield with a +1/+1 counter on it for each time it was kicked.
2 /
2
{1}{G}
Explore
Sorcery
You may play an additional land this turn.
Draw a card.
{2}{G}
Filigree Fracture
Instant
Destroy target artifact or enchantment. If that permanent was blue or black, draw a card.
{1}{G}
Gift of Strength
Instant
Target creature gets +3/+3 and gains reach until end of turn.
{1}{G}
Gleeful Sabotage
Sorcery
Destroy target artifact or enchantment.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)
{1}{U}
Halimar Wavewatch
Creature - Merfolk Soldier
Level up {2} ({2}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-4
0/6
LEVEL 5+
6/6
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
0 /
3
{3}{G}
Hunt the Weak
Sorcery
Put a +1/+1 counter on target creature you control. Then that creature fights target creature you don't control. (Each deals damage equal to its power to the other.)
{5}{U}{U}
Into the Story
Instant
This spell costs {3} less to cast if an opponent has seven or more cards in their graveyard.
Draw four cards.
{2}{G}
Invigorating Surge
Instant
Put a +1/+1 counter on target creature you control, then double the number of +1/+1 counters on that creature.
{2}{G}
Jungleborn Pioneer
Creature - Merfolk Scout
When Jungleborn Pioneer enters the battlefield, create a 1/1 blue Merfolk creature token with hexproof. (It can't be the target of spells or abilities your opponents control.)
2 /
2
{1}{U}
Kasmina's Transmutation
Enchantment - Aura
Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.
{2}{U}
Library Larcenist
Creature - Merfolk Rogue
Whenever Library Larcenist attacks, draw a card.
1 /
2
{3}{G}
Lifecrafter's Gift
Instant
Put a +1/+1 counter on target creature, then put a +1/+1 counter on each creature you control with a +1/+1 counter on it.
{1}{U}
Mana Leak
Instant
Counter target spell unless its controller pays {3}.
{1}{U}
Merfolk Looter
Creature - Merfolk Rogue
{T}: Draw a card, then discard a card.
1 /
1
{U}{ // }{U}
Merfolk Secretkeeper // Venture Deeper
Creature - Merfolk Wizard // Sorcery - Adventure
Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)
0 /
4
{2}{U}
Merfolk Thaumaturgist
Creature - Merfolk Wizard
{T}: Switch target creature's power and toughness until end of turn.
1 /
2
{G}
Might of the Masses
Instant
Target creature gets +1/+1 until end of turn for each creature you control.
{2}{U}
Nyxborn Triton
Enchantment Creature - Merfolk
Bestow {4}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Enchanted creature gets +2/+3.
2 /
3
{2}
Pillar of Origins
Artifact
As Pillar of Origins enters the battlefield, choose a creature type.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.
{1}{G}{U}
Primal Empathy
Enchantment
At the beginning of your upkeep, draw a card if you control a creature with the greatest power among creatures on the battlefield. Otherwise, put a +1/+1 counter on a creature you control.
{4}{U}{U}
Prying Eyes
Instant
Draw four cards, then discard two cards.
{5}
Psychosis Crawler
Artifact Creature - Phyrexian Horror
Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.
* /
*
{2}{U}
Release to the Wind
Instant
Exile target nonland permanent. For as long as that card remains exiled, its owner may cast it without paying its mana cost.
{3}
Rhonas's Monument
Legendary Artifact
Green creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature you control gets +2/+2 and gains trample until end of turn.
{3}{U}
Riverwise Augur
Creature - Merfolk Wizard
When Riverwise Augur enters the battlefield, draw three cards, then put two cards from your hand on top of your library in any order.
2 /
2
{2}{U}
Rousing Read
Enchantment - Aura
Enchant creature
When Rousing Read enters the battlefield, draw two cards, then discard a card.
Enchanted creature gets +1/+1 and has flying.
{4}{U}
Sage of the Falls
Creature - Merfolk Wizard
Whenever Sage of the Falls or another non-Human creature enters the battlefield under your control, you may draw a card. If you do, discard a card.
2 /
5
{2}{G}{U}
Sharktocrab
Creature - Shark Octopus Crab
{2}{G}{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 Sharktocrab, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
4 /
4
{1}
Silent Gravestone
Artifact
Cards in graveyards can't be the targets of spells or abilities.
{4}, {T}: Exile Silent Gravestone and all cards from all graveyards. Draw a card.
{3}
Simic Locket
Artifact
{T}: Add {G} or {U}.
{G/U}{G/U}{G/U}{G/U}, {T}, Sacrifice Simic Locket: Draw two cards.
{1}
Skeleton Key
Artifact - Equipment
Equipped creature has skulk. (It can't be blocked by creatures with greater power.)
Whenever equipped creature deals combat damage to a player, you may draw a card. If you do, discard a card.
Equip {2}
{U}
Spell Pierce
Instant
Counter target noncreature spell unless its controller pays {2}.
{4}{G}{G}
Strength of the Pack
Sorcery
Put two +1/+1 counters on each creature you control.
{1}{G}{G}
Swift Warden
Creature - Merfolk Warrior
Flash
When Swift Warden enters the battlefield, target Merfolk you control gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.
Creatures you control get +1/+1.
{X}{G}
Thrive
Sorcery
Put a +1/+1 counter on each of X target creatures.
{2}{G}
Tishana's Wayfinder
Creature - Merfolk Scout
When Tishana's Wayfinder enters the battlefield, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)
2 /
2
{4}{G}
Vivid Revival
Sorcery
Return up to three target multicolored cards from your graveyard to your hand. Exile Vivid Revival.
{2}{G}{G}
Waker of the Wilds
Creature - Merfolk Shaman
{X}{G}{G}: Put X +1/+1 counters on target land you control. That land becomes a 0/0 Elemental creature with haste. It's still a land.
3 /
3
{1}{U}{U}
Waterknot
Enchantment - Aura
Enchant creature
When Waterknot enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{2}{U}
Wavebreak Hippocamp
Enchantment Creature - Horse Fish
Whenever you cast your first spell during each opponent's turn, draw a card.
2 /
2
{3}{G}
Wild Onslaught
Instant
Kicker {4} (You may pay an additional {4} as you cast this spell.)
Put a +1/+1 counter on each creature you control. If this spell was kicked, put two +1/+1 counters on each creature you control instead.
{2}{G}
Wildsize
Instant
Target creature gets +2/+2 and gains trample until end of turn.
Draw a card.
{1}{G}
Wilt
Instant
Destroy target artifact or enchantment.
Cycling {2} ({2}, Discard this card: Draw a card.)