Islandwalk (This creature can't be blocked as long as defending player controls an Island.) {2}{U}: Tap target creature without flying.

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.)

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) When this creature enters, you may search your library for a Merfolk card, reveal it, then shuffle and put that card on top.

As this artifact enters, choose a creature type. Whenever you cast a spell of the chosen type, put a charge counter on this artifact. Creatures you control of the chosen type get +1/+1 for each charge counter on this artifact.

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.

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 two cards. Then discard a card unless you attacked this turn.

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.

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}.

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

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

Enchant land When this Aura enters, draw a card. Enchanted land is an Island.

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}.)

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.

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.

As this artifact enters, choose a color. Creatures you control of the chosen color get +1/+0. {T}: Add one mana of the chosen color.

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.

Flying When this creature enters, reveal the top three cards of your library. Put all Island cards revealed this way into your hand and the rest on the bottom of your library in any order.

{T}: Add {C}. {1}, {T}, Sacrifice this artifact: Draw a card.

As this artifact enters, choose a creature type. Creatures you control of the chosen type get +1/+1. {T}: Add one mana of any color.

Blue spells you cast cost {1} less to cast.

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

Untap all nonland permanents you control.

Blue creatures you control can't be blocked.

This creature can't be blocked. This creature gets +2/+0 as long as you control a commander that's a creature or planeswalker.

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

Trample Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Shroud (This creature can't be the target of spells or abilities.)

This creature can't be blocked.

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

This creature can't be blocked. Whenever another Merfolk you control enters, this creature gets +1/+1 until end of turn.

Enchant land (Target a land as you cast this. This card enters attached to that land.) Enchanted land is an Island.

{T}: Target Merfolk creature gets +1/+1 and gains islandwalk until end of turn. (It can't be blocked as long as defending player controls an Island.) {T}: Target land becomes an Island until end of turn.

When this creature enters, 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.

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

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

This creature can't be blocked.

Counter target spell.

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

Flash This spell can't be countered. Whenever you cast a spell, choose up to one — • Return target spell you don't control to its owner's hand. • Return target nonland permanent to its owner's hand.

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

When this creature enters, return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.

Return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control. Foretell {1}{U}{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.)

Counter target spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

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}.

({T}: Add {U}.)

({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.

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

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.)