Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

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

{T}: Add {G}.

{T}: Add {U}.

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

{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.

Prevent all damage that would be dealt to creatures this turn. Creatures you control gain hexproof until end of turn. (They can't be the targets of spells or abilities your opponents control.)

{T}: Add {G}.

Channel -- {1}{G}, Discard Boseiju, Who Endures: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Botanical Sanctum enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {G} or {U}.

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, you may draw a card.

({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.

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.

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

Counter target spell.

Enchant creature

Whenever enchanted creature deals damage to an opponent, you may draw a card.

At the beginning of combat on your turn, Deepfathom Echo explores. Then you may have it become a copy of another creature you control until end of turn. (To have this creature explore, 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.)

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

Merfolk and Druid cards in your graveyard have retrace. (You may cast cards with retrace from your graveyard by discarding a land card in addition to paying their other costs.)

Whenever one or more nontoken Merfolk you control become tapped, create a 1/1 blue Merfolk creature token with hexproof.

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.)

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

Dreamroot Cascade enters the battlefield tapped unless you control two or more other lands.

{T}: Add {G} or {U}.

You may look at the top card of your library any time.

You may cast Merfolk spells from the top of your library.

Whenever you cast a Merfolk spell, you may pay {1}. If you do, create a 1/1 blue Merfolk creature token.

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

({T}: Add {G}.)

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control. Then if that creature has three or more +1/+1 counters on it, transform Hadana's Climb.

(Transforms from Hadana's Climb.)

{T}: Add one mana of any color.

{1}{G}{U}, {T}: Target creature you control gains flying and gets +X/+X until end of turn, where X is its power.

At the beginning of combat on your turn, each Merfolk creature you control 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 the exploring creature, then put the card back or put it into your graveyard.)

Whenever Hakbal of the Surging Soul attacks, you may put a land card from your hand onto the battlefield. If you don't, draw a card.

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

({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.)

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

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

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.

{T}: Add {G} or {U}.

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

{T}: Add {C}.

{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

As Kindred Discovery enters the battlefield, choose a creature type.

Whenever a creature you control of the chosen type enters the battlefield or attacks, draw a card.

{T}: Untap another target permanent.

+1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.

-1: Draw a card. You may play an additional land this turn.

-5: You get an emblem with "At the beginning of your end step, create a 9/9 blue Kraken creature token."

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.

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.

Tap another untapped Merfolk you control: Kumena, Tyrant of Orazca can't be blocked this turn.

Tap three untapped Merfolk you control: Draw a card.

Tap five untapped Merfolk you control: Put a +1/+1 counter on each Merfolk you control.

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

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

Whenever a creature you control explores, Merfolk Cave-Diver gets +1/+0 until end of turn and can't be blocked this turn.

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.

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.

Flying

Other Merfolk you control get +1/+0 and have flying.

Encore {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Mist-Cloaked Herald can't be blocked.

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

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

Whenever a creature you control explores a land card, you may put a land card from your hand onto the battlefield tapped.

Whenever a creature you control explores a nonland card, put a +1/+1 counter on Nicanzil, Current Conductor.

{T}: Add {U}.

Channel -- {3}{U}, Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

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.

Rejuvenating Springs enters the battlefield tapped unless you have two or more opponents.

{T}: Add {G} or {U}.

You have no maximum hand size.

{T}: Add {C}.

Proliferate, then choose any number of permanents you control that had a counter put on them this way. Those permanents phase out. (To proliferate, choose any number of permanents and/or players, then give each another counter of each kind already there. Treat phased-out permanents and anything attached to them as though they don't exist until their controller's next turn.)

When Rishkar, Peema Renegade enters the battlefield, put a +1/+1 counter on each of up to two target creatures.

Each creature you control with a counter on it has "{T}: Add {G}."

Ward {2}

As Roaming Throne enters the battlefield, choose a creature type.

Roaming Throne is the chosen type in addition to its other types.

If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

{T}: Add {C}.

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

Each other Wizard creature you control enters the battlefield with an additional +1/+1 counter on it.

{2}, Remove a +1/+1 counter from a creature you control: Draw a card.

Draw cards equal to the number of cards in your hand plus one. You have no maximum hand size for the rest of the game.

As Sea Gate, Reborn enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.

{T}: Add {U}.

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

Equipped creature gets +1/+1 and has trample and lifelink.

{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.

Equip {2}

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.

Flash

When Singer of Swift Rivers enters the battlefield, put a shield counter on another target creature you control. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

You may cast Merfolk spells as though they had flash.

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

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.

Counter target noncreature spell unless its controller pays {1}.

Ferocious -- If you control a creature with power 4 or greater, counter that spell instead.

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

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}.)

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

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

Temple of Mystery enters the battlefield tapped.

When Temple of Mystery enters the battlefield, scry 1.

{T}: Add {G} or {U}.

This spell costs {X} less to cast, where X is the greatest power among creatures you control.

{T}: Add {G}{G}. You gain 2 life.

Whenever a nontoken creature enters the battlefield under your control, put a +1/+1 counter on it and draw a card.

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.

Flash

When Tishana's Tidebinder enters the battlefield, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as Tishana's Tidebinder remains on the battlefield. (Mana abilities can't be targeted.)

When Topography Tracker enters the battlefield, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

If a creature you control would explore, instead it explores, then it explores again.

If a permanent entering the battlefield causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

---

Copy target activated or triggered ability you control. You may choose new targets for the copy.

Flash

Other Merfolk you control get +1/+1.

Sacrifice a Merfolk: Counter target noncreature spell unless its controller pays {1}.

Return X target cards from your graveyard to your hand. Exile Wildest Dreams.

Flying

As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Woodland Stream enters the battlefield tapped.

{T}: Add {G} or {U}.

+1: Reveal the top four cards of your library. Put all land cards revealed this way into your hand and the rest into your graveyard.

0: Put any number of land cards from your hand onto the battlefield tapped.

-3: Create a green Treefolk creature token with reach and "This creature's power and toughness are each equal to the number of lands you control."

-8: Return all permanent cards from your graveyard to your hand. You get an emblem with "You have no maximum hand size."

Whenever Xolatoyac, the Smiling Flood enters the battlefield or attacks, 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.

At the beginning of your end step, untap each permanent you control with a counter on it.

{T}: Add {C}.

{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Each land is a Forest in addition to its other land types.

When Zegana, Utopian Speaker enters the battlefield, if you control another creature with a +1/+1 counter on it, draw a card.

{4}{G}{U}: Adapt 4. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

Each creature you control with a +1/+1 counter on it has trample.