Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Creatures you control have "Whenever one or more counters are put on this creature for the first time each turn, draw a card."

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.)

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

{T}: Add {G}. Channel — {1}{G}, Discard this card: 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.

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

As this land enters, 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.

This land enters tapped unless you control two or more other lands. {T}: Add {G} or {U}.

({T}: Add {G}.)

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

This land enters tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

({T}: Add {U}.)

Draw three cards. Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

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

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

{T}: Add {U}. Channel — {3}{U}, Discard this card: 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.

{T}: Add {C}. {T}: Add one mana of any color. Spend this mana only to cast a legendary spell. {T}: Add one mana of any color among legendary permanents you control. {3}, {T}, Exile this land: Target legendary creature gains hexproof and indestructible until end of turn.

{T}: Add one mana of any type that a land you control could produce.

This land enters tapped unless you have two or more opponents. {T}: Add {G} or {U}.

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

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

This land enters tapped. When this land enters, return a land you control to its owner's hand. {T}: Add {G}{U}.

As Three Tree City enters, choose a creature type. {T}: Add {C}. {2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

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

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.

Counter target spell.

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.) Counter target creature spell. If the gift was promised, instead counter target spell.

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

You have no maximum hand size. {T}: Add one mana of any color.

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on that permanent instead. {T}: Add X mana of any one color, where X is this creature's power.

Reach Modified creatures you control have trample. (Equipment, Auras you control, and counters are modifications.) Whenever a modified creature you control deals combat damage to a player, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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

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

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

Blue creatures you control can't be blocked.

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.

Flash Vigilance When this creature enters, tap target creature an opponent controls and put a stun counter on it. {1}{U}, {T}: Shuffle this creature and target creature with a stun counter on it into their owners' libraries.

This creature can't be blocked. This creature gets +2/+0 as long as you control a commander that's a creature or planeswalker.

Nonbasic lands are Islands.

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

When Kiora enters, draw two cards, then discard two cards. Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Whenever this creature attacks, draw a card.

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.)

Other Merfolk you control get +1/+1.

Flying When this creature enters, put a +1/+1 counter on target creature you control. {3}{G}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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

Flash When this creature enters, 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.

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.)

This creature can't be blocked.

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.

This creature can't be blocked. Whenever another Merfolk you control enters, this creature gets +1/+1 until end of turn.

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

Vigilance Whenever this creature enters or attacks, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")

Svyelun 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}.)

When this creature enters, tap all creatures target opponent controls.

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

{T}: Target land becomes the basic land type of your choice until end of turn. Activate only during your turn.

Flash When this creature enters, 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 this creature remains on the battlefield. (Mana abilities can't be targeted.)

As this creature enters, choose a creature type. This creature is the chosen type in addition to its other types. Whenever this creature enters or attacks, you may draw a card for each other creature you control that shares a creature type with it. If you do, discard a card.

When this creature enters, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.") If a creature you control would explore, instead it explores, then it explores again.

This creature can't be blocked.

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

Champion a Merfolk (When this enters, sacrifice it unless you exile another Merfolk you control. When this leaves the battlefield, that card returns to the battlefield.) Whenever this creature deals combat damage to a player, you may sacrifice a Merfolk. If you do, take an extra turn after this one.

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

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.")

Change the text of target spell or permanent by replacing all instances of one basic land type with another. (For example, you may change "swampwalk" to "plainswalk." This effect lasts indefinitely.)

Destroy target artifact or enchantment. Its controller gains 4 life.

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

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

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