{T}: Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.) Equip {0}

{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.

When Thassa's Oracle enters the battlefield, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

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.

Whenever Deeproot Wayfinder deals combat damage to a player or battle, surveil 1, then you may return a land card from your graveyard to the battlefield tapped. (To surveil 1, look at the top card of your library. You may put that card into your graveyard.)

Flying As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay. Whenever you cast a blue permanent spell, draw a card.

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.

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

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.)

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.

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

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.

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

When Merfolk Branchwalker 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.)

Other Merfolk you control get +1/+1.

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

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

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

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

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) {1}, {T}: Tap target land.

{3}, {T}: Search your library for a Merfolk permanent card, put it onto the battlefield, then shuffle.

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.

When Tempest Caller enters the battlefield, tap all creatures target opponent controls.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that card.

Indestructible As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.) At the beginning of your upkeep, scry 1. {1}{U}: Target creature you control can't be blocked this turn.

Kicker {X}. X can't be 0. (You may pay an additional {X} as you cast this spell.) Flying When Thieving Skydiver enters the battlefield, if it was kicked, gain control of target artifact with mana value X or less. If that artifact is an Equipment, attach it to Thieving Skydiver.

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.

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

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.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever Cold-Eyed Selkie deals combat damage to a player, you may draw that many cards.

Whenever Fallowsage becomes tapped, you may draw a card.

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.

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}.)

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life and draw a card.

{4}: Scry 1, then reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. Otherwise, draw a card. Partner (You can have two commanders if both have partner.)

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.)

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield. You may cast spells as though they had flash.

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

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.

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Counter target spell.

Permanents you control gain hexproof and indestructible until end of turn.

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Botanical Sanctum enters the battlefield tapped unless you control two or fewer other lands. {T}: Add {G} or {U}.

({T}: Add {G} or {U}.) As Breeding Pool enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Castle Vantress enters the battlefield tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

As Cavern of Souls enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

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

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

({T}: Add {G}.)

({T}: Add {G} or {U}.) Hedge Maze enters the battlefield tapped. When Hedge Maze enters the battlefield, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

({T}: Add {U}.)

{T}: Add {U}. {U}, {T}: Untap target legendary permanent.

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

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

({T}: Add {U}.) Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands. When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Path of Ancestry enters the battlefield tapped. {T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

({T}: Add {G} or {U}.) Rimewood Falls enters the battlefield tapped.

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Temple of Mystery enters the battlefield tapped. When Temple of Mystery enters the battlefield, scry 1. {T}: Add {G} or {U}.

As Unclaimed Territory enters the battlefield, choose a creature type. {T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped. {T}: Add {G} or {U}.

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

{T}, Pay 1 life: Add {G} or {U}. {1}, {T}, Sacrifice Waterlogged Grove: Draw a card.

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

Creatures you control have "{T}: Add one mana of any color."

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Draw a card. You may put a land card from your hand onto the battlefield.

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.

{T}: Untap another target permanent.

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

{T}: Add {C}{C}.

{T}: Add {C}. {T}: Add {G} or {U}. Talisman of Curiosity deals 1 damage to you.

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension. As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

{U}{U}, {T}: Gain control of target legendary permanent. (This effect lasts indefinitely.)

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.

You can't cast this spell during your first, second, or third turns of the game. +1: Draw a card, then discard a card. +1: You may exile a nonland card with mana value 3 or less from your hand. If you do, it becomes plotted. −6: Until end of turn, whenever you cast a spell, copy it. You may choose new targets for the copy.

Choose a creature type. Reveal cards from the top of your library until you reveal X creature cards of the chosen type, where X is the number of creatures you control of that type. Put those cards onto the battlefield, then shuffle the rest of the revealed cards into your library.

Changeling (This card is every creature type.) When Masked Vandal enters the battlefield, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

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.)

Counter target noncreature spell.

Whenever a creature you control becomes the target of a spell or ability an opponent controls, you may draw a card.

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.

{T}: Add {C}. {3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

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

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

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

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.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost. Counter target spell.

{T}: Add {C}. {T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Halimar Depths enters the battlefield tapped. When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order. {T}: Add {U}.

Flash If an opponent would draw a card except the first one they draw in each of their draw steps, instead you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Each creature you control with a +1/+1 counter on it has "{T}: Add one mana of any color." −1: Put a +1/+1 counter on target creature.

+1: Untap up to one target creature and up to one target land. −2: Reveal the top four cards of your library. You may put a creature card and/or a land card from among them into your hand. Put the rest into your graveyard. −8: You get an emblem with "Whenever a creature enters the battlefield under your control, you may have it fight target creature." Then create three 8/8 blue Octopus creature tokens.

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Lumbering Falls enters the battlefield tapped. {T}: Add {G} or {U}. {2}{G}{U}: Lumbering Falls becomes a 3/3 green and blue Elemental creature with hexproof until end of turn. It's still a land.

+2: Scry 2. 0: Look at the top card of your library. If it's a land card or a creature card with mana value less than or equal to the number of loyalty counters on Nissa, Steward of Elements, you may put that card onto the battlefield. −6: Untap up to two target lands you control. They become 5/5 Elemental creatures with flying and haste until end of turn. They're still lands.

{T}: Add {C}. {G}{U}, {T}: Put a +1/+1 counter on each creature that entered the battlefield this turn.

Oran-Rief, the Vastwood enters the battlefield tapped. {T}: Add {G}. {T}: Put a +1/+1 counter on each green creature that entered the battlefield this turn.

You have no maximum hand size. {T}: Add {C}.

Choose one — • Destroy target artifact. • Destroy target enchantment. • Exile target card from a graveyard.

Return all nonland permanents target player controls to their owner's hand.

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.

Choose one — • Target creature gets +3/+3 until end of turn. • Permanents you control gain hexproof until end of turn. • Return target creature to its owner's hand.

Simic Growth Chamber enters the battlefield tapped. When Simic Growth Chamber enters the battlefield, return a land you control to its owner's hand. {T}: Add {G}{U}.

{1}, {T}: Add {G}{U}.

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.) When Slinn Voda, the Rising Deep enters the battlefield, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

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

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Thornwood Falls enters the battlefield tapped. When Thornwood Falls enters the battlefield, you gain 1 life. {T}: Add {G} or {U}.

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

As Vanquisher's Banner enters the battlefield, choose a creature type. Creatures you control of the chosen type get +1/+1. Whenever you cast a creature spell of the chosen type, draw a card.

When Vineshaper Mystic enters the battlefield, put a +1/+1 counter on each of up to two target Merfolk you control.

Vivid Creek enters the battlefield tapped with two charge counters on it. {T}: Add {U}. {T}, Remove a charge counter from Vivid Creek: Add one mana of any color.

Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on target Merfolk you control.

Dreamroot Cascade enters the battlefield tapped unless you control two or more other lands. {T}: Add {G} or {U}.

If you control a commander, you may cast this spell without paying its mana cost. Counter target noncreature spell.

When Forerunner of the Heralds enters the battlefield, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top. Whenever another Merfolk enters the battlefield under your control, put a +1/+1 counter on Forerunner of the Heralds.

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

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.

Other green creatures you control get +1/+1. Other blue creatures you control get +1/+1. Untap all green and/or blue creatures you control during each other player's untap step.

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

Changeling (This card is every creature type.) As Realmwalker enters the battlefield, choose a creature type. You may look at the top card of your library any time. You may cast creature spells of the chosen type from the top of your library.

As Reflections of Littjara enters the battlefield, choose a creature type. Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents. {T}: Add {G} or {U}.

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Whenever equipped creature deals combat damage to a player, you draw that many cards. Equip {4} Equip Shaman, Warlock, or Wizard {1}

Untap all permanents you control during each other player's untap step.

Whenever Surgespanner becomes tapped, you may pay {1}{U}. If you do, return target permanent to its owner's hand.