Nonbasic lands are Islands.

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 another Merfolk you control enters, this creature gets +1/+1 until end of turn.

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.

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

Kicker {1} (You may pay an additional {1} as you cast this spell.) When this creature enters, if it was kicked, target land becomes an Island for as long as this creature remains on the battlefield. This creature gets +1/+1 as long as an opponent controls an Island.

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

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.

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.

({T}: Add {U}.)

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

As this enchantment enters, 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.)

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

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.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) All lands are Islands in addition to their other types. Creatures without flying or islandwalk can't attack.

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.

Counter target spell unless its controller pays {3}.

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

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

Flying As an additional cost to cast blue permanent spells, you may pay 2 life. Those spells cost {U} less to cast if you paid life this way. This effect reduces only the amount of blue mana you pay. Whenever you cast a blue permanent spell, draw a card.

As this artifact enters, 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.

{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}.

{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.

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.

Draw three cards, then put two cards from your hand on top of your library in any order.

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.) Draw a card.

Enchant creature Whenever enchanted creature deals damage to an opponent, you may draw a card.

Scry 2, then draw a card.

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.

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.

As this artifact enters, choose a creature type. Creatures you control of the chosen type get +1/+1. {3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

As this enchantment enters, choose a creature type. Whenever a creature you control of the chosen type enters or attacks, draw a card.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.) Draw a card.

Look at the top three cards of your library, then put them back in any order. You may shuffle. Draw a card.

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

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

Draw a card. Scry 2.

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.

You have no maximum hand size. At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game. {3}{U}: Draw a card.

As this artifact enters, choose a creature type. Creatures you control of the chosen type get +1/+1. Whenever you cast a creature spell of the chosen type, draw a card.

Return all attacking creatures to their owner's hand.

Counter target spell.

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Return all noncreature, nonland permanents to their owners' hands.

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.

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.)

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.) When Slinn Voda enters, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

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

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.