Blue creatures you control can't be blocked.

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

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.)

If an opponent controls a Mountain and you control an Island, you may cast this spell without paying its mana cost. Flying

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.

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

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.

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

{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.

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

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

When this creature enters, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top. Whenever another Merfolk you control enters, put a +1/+1 counter on this creature.

{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.

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

This land enters tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

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

{T}: Add {C}. {G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{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}.)

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.) This land enters tapped. {T}: Add {G}. {G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

({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.

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

This land enters 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.)

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}.

This land enters tapped. When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.) {T}: Add {G} or {U}.

Return all attacking creatures to their owner's hand.

Counter target spell.

This spell has flash as long as you control a Merfolk. Return target creature to its owner's hand. Draw a card.

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

You may sacrifice a nontoken blue creature rather than pay this spell's mana cost. Counter target spell.

You may cast this card 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 this creature enters, you may return target tapped creature an opponent controls to its owner's hand.

Flash When this creature enters, tap target creature an opponent controls. It loses all abilities until end of turn.

Counter target noncreature spell.

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

{U}: This creature gains flying until end of turn. Whenever this creature 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.

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.

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.)

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

{U}, {T}: Counter target spell unless its controller pays {1}.

Whenever this creature attacks and isn't blocked, look at the top card of defending player's library. You may put that card on the bottom of that player's library.

{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 this creature, draw a card, then discard a card.

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

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.

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.)

Tap another untapped Merfolk you control: Kumena 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.

Prime Speaker Zegana enters with X +1/+1 counters on it, where X is the greatest power among other creatures you control. When Prime Speaker Zegana enters, draw cards equal to its power.

Changeling (This card is every creature type.) As this creature enters, 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.

When this creature enters, draw three cards, then put two cards from your hand on top of your library in any order.

Whenever this creature becomes blocked, you may draw three cards.

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

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, 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.)

{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.)

When this creature enters, reveal the top four cards of your library. Put all Merfolk cards revealed this way into your hand and the rest on the bottom of your library in any order. {3}{U}: This creature gains flying until end of turn.

Tishana's power and toughness are each equal to the number of cards in your hand. You have no maximum hand size. When Tishana enters, draw a card for each creature you control.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.) Whenever a creature you control with a +1/+1 counter on it dies, draw a card.

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.

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.)