When Breaching Leviathan enters the battlefield, if you cast it from your hand, tap all nonblue creatures. Those creatures don't untap during their controllers' next untap steps.

Counter target spell.

Cloudpost enters the battlefield tapped.

{T}: Add {C} for each Locus on the battlefield.

Surge {3}{U}{U} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)

Return all nonland permanents to their owners' hands. If this spell's surge cost was paid, create an 8/8 blue Octopus creature token.

Deep-Sea Kraken can't be blocked.

Suspend 9--{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

Deep-Sea Kraken can't be blocked.

Suspend 9--{2}{U} (Rather than cast this card from your hand, you may pay {2}{U} and exile it with nine time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, cast it without paying its mana cost. It has haste.)

Whenever an opponent casts a spell, if Deep-Sea Kraken is suspended, remove a time counter from it.

Desert of the Mindful enters the battlefield tapped.

{T}: Add {U}.

Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

{U}{U}: Tap target creature without flying.

Defender, flying

Prevent all combat damage that would be dealt to and dealt by Fog Bank.

{T}: Add three mana of any one color.

When Glimmerpost enters the battlefield, you gain 1 life for each Locus on the battlefield.

{T}: Add {C}.

Halimar Depths enters tapped.

When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.

{T}: Add {U}.

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

{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

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

Tap X target creatures.

Ferocious -- If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

{2}{U}, {T}, Sacrifice another creature: Reveal cards from the top of your library until you reveal a nonlegendary creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Whenever a player casts a blue spell, you may gain 1 life.

Whenever Lorthos, the Tidemaker attacks, you may pay {8}. If you do, tap up to eight target permanents. Those permanents don't untap during their controllers' next untap steps.

When Man-o'-War enters, return target creature to its owner's hand.

Counter target noncreature spell.

This spell can't be countered.

You have no maximum hand size.

Whenever an opponent casts a noncreature spell, draw a card.

Discard three cards: Exile Nezahal, Primal Tide. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

At the beginning of your upkeep, you may look at the top card of your library. If it's a creature card, you may reveal it and put a quest counter on Quest for Ula's Temple.

At the beginning of each end step, if there are three or more quest counters on Quest for Ula's Temple, you may put a Kraken, Leviathan, Octopus, or Serpent creature card from your hand onto the battlefield.

When Reef Worm dies, create a 3/3 blue Fish creature token with "When this creature dies, create a 6/6 blue Whale creature token with 'When this creature dies, create a 9/9 blue Kraken creature token.'"

Draw a card. Clash with an opponent. If you win, return Research the Deep to its owner's hand. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

When Scourge of Fleets enters the battlefield, 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.

Serpent of the Endless Sea's power and toughness are each equal to the number of Islands you control.

Serpent of the Endless Sea can't attack unless defending player controls an Island.

{6}{U}{U}: Monstrosity 4. (If this creature isn't monstrous, put four +1/+1 counters on it and it becomes monstrous.)

When Shipbreaker Kraken becomes monstrous, tap up to four target creatures. Those creatures don't untap during their controllers' untap steps for as long as you control Shipbreaker Kraken.

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.)

All lands are Islands in addition to their other types.

Creatures without flying or islandwalk can't attack.

Reveal cards from the top of your library until you reveal a nonland card, then put all cards revealed this way into your hand.

Tromokratis has hexproof unless it's attacking or blocking.

Tromokratis can't be blocked unless all creatures defending player controls block it. (If any creature that player controls doesn't block this creature, it can't be blocked.)

Return target creature to its owner's hand.

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

Defender

Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Return all creatures to their owners' hands except for Krakens, Leviathans, Octopuses, and Serpents.