Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Level up {1} ({1}: Put a level counter on this. Level up only as a sorcery.) LEVEL 2-3 3/3 Flying LEVEL 4+ 4/4 Flying Other Merfolk creatures you control get +1/+1.

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.

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.) Equip {0}

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.

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

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.

Kicker {5} (You may pay an additional {5} as you cast this spell.) Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

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.

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it. Equip {2}

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.) Equip {1}

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.

Choose two — • Counter target spell. • Return target permanent to its owner's hand. • Tap all creatures your opponents control. • Draw a card.

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

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.")

As an additional cost to cast this spell, return a creature you control to its owner's hand. Counter target spell.

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token. Tap seven untapped Merfolk you control: Counter target spell.

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Each player shuffles their hand and graveyard into their library, then draws seven cards. If it's your turn, end the turn. (Exile all spells and abilities from the stack, including this card. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

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.

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.

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

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

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) When Shipwreck Dowser enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

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.

Nonbasic lands don't untap during their controllers' untap steps.

At the beginning of each player's upkeep, that player puts a flood counter on target non-Island land they control of their choice. That land is an Island for as long as it has a flood counter on it. At the beginning of each end step, if all lands on the battlefield are Islands, remove all flood counters from them.

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

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) {1}, {T}: Tap target land.

{U}: Rootwater Thief gains flying until end of turn. Whenever Rootwater Thief 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 {1}{U} (You may pay an additional {1}{U} as you cast this spell.) When Slinn Voda, the Rising Deep enters the battlefield, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever Thada Adel, Acquisitor deals combat damage to a player, search that player's library for an artifact card and exile it. Then that player shuffles. Until end of turn, you may play that 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.

{T}: Target land becomes an Island until end of turn.

{T}: Add {C}. {1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Coral Atoll enters the battlefield tapped. When Coral Atoll enters the battlefield, sacrifice it unless you return an untapped Island you control to its owner's hand. {T}: Add {C}{U}.

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.

({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 {C}. {2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

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

{T}: Add {C}. {1}, {T}: Tap target land.

{T}: Add {C}. {2}, {T}, Sacrifice a Desert: Exile all graveyards.

({T}: Add {U}.)

{T}: Add {C}. {2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

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

As Caged Sun enters the battlefield, choose a color. Creatures you control of the chosen color get +1/+1. Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

{T}: Add one mana of any color that a land an opponent controls could produce.

As Herald's Horn enters the battlefield, choose a creature type. Creature spells you cast of the chosen type cost {1} less to cast. At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Blue creature spells you cast cost {1} less to cast. Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

{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.

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

Whenever you cast a creature spell, you may pay {1}. If you do, return target creature to its owner's hand.

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.

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

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

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

Whenever a creature you control becomes blocked, you may return it to its owner's hand.

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.)

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield. You may cast spells as though they had flash.

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

Level up {1}{U} ({1}{U}: Put a level counter on this. Level up only as a sorcery.) LEVEL 1-2 0/1 {T}: Draw a card, then discard a card. LEVEL 3+ 0/1 {T}: Draw a card.