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

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy. {3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. {4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

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.)

Ascendant Acolyte enters the battlefield with a +1/+1 counter on it for each +1/+1 counter among other creatures you control. At the beginning of your upkeep, double the number of +1/+1 counters on Ascendant Acolyte.

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

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.

{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.

Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith. At the beginning of combat on your turn, if The Ozolith has counters on it, you may move all counters from The Ozolith onto target creature.

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."

{T}: Untap another target permanent you control. {T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

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

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.)

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.

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.

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.

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.)

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.

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.

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.

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

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}.)

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

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

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.

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

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.)

Counter target spell unless its controller pays {2}. Suspect up to one target creature. (A suspected creature has menace and can't block.)

Put X +1/+1 counters on target creature you control. Then counter up to one target spell unless its controller pays mana equal to the greatest power among creatures you control.

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

{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}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

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

As Secluded Courtyard 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 or activate an ability of a creature source of the chosen type.

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}.

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

Thriving Isle enters the battlefield tapped. As Thriving Isle enters the battlefield, choose a color other than blue. {T}: Add {U} or one mana of the chosen color.

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}.

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 Indestructible When Mithril Coat enters the battlefield, attach it to target legendary creature you control. Equipped creature has indestructible. Equip {3}

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

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

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

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

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

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

Return all attacking creatures to their owner's hand.

Counter target noncreature spell.

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.

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying. Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

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.

Until end of turn, creatures you control get +1/+1 and gain trample and infect. (Creatures with infect deal damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

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.)

When Aquatic Incursion enters the battlefield, create two 1/1 blue Merfolk creature tokens with hexproof. (They can't be the targets of spells or abilities your opponents control.) {3}{U}: Target Merfolk can't be blocked this turn.

Trample Whenever a player casts a spell, put a +1/+1 counter on Managorger Hydra.

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

You may have Auton Soldier enter the battlefield as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it attacks, for each opponent other than defending player, you may put a token that's a copy of this creature onto the battlefield tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

At the beginning of each upkeep, untap all creatures and lands.

{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.

Descend 8 — When you cast this spell, if there are eight or more permanent cards in your graveyard, copy this spell twice. You may choose new targets for the copies. Return target permanent card from your graveyard to your hand. Exile Bygone Marvels.

{T}: Add {C}. {1}, {T}: Add one mana of any color. {4}, {T}, Sacrifice Captivating Cave: Put two +1/+1 counters on target creature. Activate only as a sorcery.

You may have Clone enter the battlefield as a copy of any creature on the battlefield.

When Court of Garenbrig enters the battlefield, you become the monarch. At the beginning of your upkeep, distribute two +1/+1 counters among up to two target creatures. Then if you're the monarch, double the number of +1/+1 counters on each creature 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.)

Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

You may play an additional land on each of your turns.

Whenever a player casts a spell, you may put a +1/+1 counter on Forgotten Ancient. At the beginning of your upkeep, you may move any number of +1/+1 counters from Forgotten Ancient onto other creatures.

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.)

Trample Kalonian Hydra enters the battlefield with four +1/+1 counters on it. Whenever Kalonian Hydra attacks, double the number of +1/+1 counters on each creature you control.

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

Llanowar Reborn enters the battlefield tapped. {T}: Add {G}. Graft 1 (This land enters the battlefield with a +1/+1 counter on it. Whenever a creature enters the battlefield, you may move a +1/+1 counter from this land onto it.)

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield. {3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Enchant artifact you control At the beginning of your upkeep, create a token that's a copy of enchanted artifact. Then if you control eight or more artifacts with the same name as one another, you win the game.

Other Merfolk you control get +1/+1.

Flying When Merfolk Skydiver enters the battlefield, 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.)

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

Whenever a creature enters the battlefield under your control, 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 the creature, then put the card back or put it into your graveyard.)

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

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Choose two — • Return target creature or planeswalker to its owner's hand. • Counter target artifact or enchantment spell. • Put two +1/+1 counters on target creature. • Target player shuffles up to three target cards from their graveyard into their library.

Storm (When you cast this spell, copy it for each spell cast before it this turn.) Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

When River Herald Scout 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.)

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

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

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

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

+1: Tap target permanent. It doesn't untap during its controller's next untap step. −2: Draw a card for each tapped creature target player controls. −8: You get an emblem with "You have no maximum hand size" and "Whenever a card is put into your graveyard from anywhere, you may return it to your hand."

You may activate loyalty abilities of Teferi, Master of Time on any player's turn any time you could cast an instant. +1: Draw a card, then discard a card. −3: Target creature you don't control phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.) −10: Take two extra turns after this one.

You may look at the top card of your library any time. As long as The Reality Chip is attached to a creature, you may play lands and cast spells from the top of your library. Reconfigure {2}{U} ({2}{U}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Tishana, Voice of Thunder's power and toughness are each equal to the number of cards in your hand. You have no maximum hand size. When Tishana enters the battlefield, 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.

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.

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

{G}{U}, {T}: Double the number of each kind of counter on target artifact, creature, or land.