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

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.

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.)

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.)

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

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.)

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.

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.

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.")

{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.

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

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.

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.)

You may look at the top card of your library any time. You may cast creature spells from the top of your library. Creatures you control have "{T}: Add one mana of any color."

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.

Whenever Fallowsage becomes tapped, you may draw a card.

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.

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.

When Jadelight Spelunker enters the battlefield, it explores X times. (To have it 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 that creature, then put the card back or put it into your graveyard.)

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.

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

All creatures have haste.

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

Creatures don't untap during their controllers' untap steps. Whenever a creature enters the battlefield, untap all creatures.

{T}: Untap another target permanent.

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

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

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.

Whenever a creature you control becomes tapped, you may put a quest counter on Quest for Renewal. As long as there are four or more quest counters on Quest for Renewal, untap all creatures you control during each other player's untap step.

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

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.

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

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

Counter target spell. At the beginning of your next precombat main phase, add X mana in any combination of colors, where X is that spell's mana value.

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard. Draw a card.

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

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.

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.)

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

{T}: Add {C}. {G}{U}, {T}: You may cast spells this turn as though they had flash.

{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.

({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.

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.

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

{T}, Sacrifice Evolving Wilds: 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}.)

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

{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 {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.

{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.

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.)

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}.

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}.

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

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

{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 a Forest card, put that card onto the battlefield, then shuffle.

{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.

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

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.

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

Whenever a nontoken creature enters the battlefield under your control, if it doesn't have the same name as another creature you control or a creature card in your graveyard, 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.

Other Merfolk you control get +1/+1.

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.

Whenever one or more creatures you control deal combat damage to a player, tap all lands that player controls and untap all lands you control.

If one or more +1/+1 counters would be put on an artifact or creature you control, that many plus one +1/+1 counters are put on it instead. {1}{G}, {T}: Put a +1/+1 counter on target artifact or creature you control. Activate only as a sorcery. Cycling {2} ({2}, Discard this card: Draw a card.)

Graft 3 (This creature enters the battlefield with three +1/+1 counters on it. Whenever another creature enters the battlefield, you may move a +1/+1 counter from this creature onto it.) {2}: Target creature with a +1/+1 counter on it gains shroud until end of turn. (It can't be the target of spells or abilities.)

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}."

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

{1}{G}{U}: Put a +1/+1 counter on target creature you control. Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy. At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.) I, II — Until your next turn, creatures you control gain "{T}: Add one mana of any color." III — Put a +1/+1 counter on each creature you control. Those creatures gain vigilance, trample, and indestructible until end of turn.

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.)

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

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.

Whenever a creature enters the battlefield under your control, draw a card if its power is 3 or greater. Otherwise, put two +1/+1 counters on it.

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