{2}, {T}: Draw a card, then discard a card. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast. {3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Whenever Marvo, Deep Operative attacks, clash with defending player. (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.) Whenever you win a clash, draw a card. Then you may cast a spell from your hand with mana value 8 or less without paying its mana cost.

Scrapdiver Serpent can't be blocked as long as defending player controls an artifact.

Sealock Monster can't attack unless defending player controls an Island. {5}{U}{U}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.) When Sealock Monster becomes monstrous, target land becomes an Island in addition to its other types.

Whenever Acquisition Octopus or equipped creature deals combat damage to a player, draw a card. Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

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.

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

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

Flash {U}, Sacrifice an Island: Lochmere Serpent can't be blocked this turn. {B}, Sacrifice a Swamp: You gain 1 life and draw a card. {U}{B}: Exile five target cards from an opponent's graveyard. Return Lochmere Serpent from your graveyard to your hand. Activate only as a sorcery.

Whenever you attack with two or more creatures, draw a card.

Whenever a creature you control deals combat damage to a player, you may draw a card. Cycling {2} ({2}, Discard this card: Draw a card.)

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, you may 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.

Creatures with power less than the number of Islands you control can't block Kraken of the Straits.

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.

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.)

Bojuka Bog enters the battlefield tapped. When Bojuka Bog enters the battlefield, exile target player's graveyard. {T}: Add {B}.

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

({T}: Add {U} or {B}.) Contaminated Aquifer enters the battlefield tapped.

Dimir Aqueduct enters the battlefield tapped. When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand. {T}: Add {U}{B}.

({T}: Add {U} or {B}.) Fetid Pools enters the battlefield tapped. Cycling {2} ({2}, Discard this card: Draw a card.)

({T}: Add {U} or {B}.) Ice Tunnel enters the battlefield tapped.

({T}: Add {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.

Path of Ancestry enters the battlefield tapped. {T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

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

({T}: Add {U} or {B}.) Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

Enchant permanent Enchanted permanent has hexproof. When enchanted permanent leaves the battlefield, if it was historic, draw two cards. (Artifacts, legendaries, and Sagas are historic.)

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

{2}: Equipped creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.) At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's blue. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

{2}: Regenerate equipped creature. (The next time that creature would be destroyed this turn, it isn't. Instead tap it, remove all damage from it, and remove it from combat.) At the beginning of your upkeep, put a +1/+1 counter on equipped creature if it's black. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

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

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

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.

When Monstrosity of the Lake enters the battlefield, you may pay {5}. If you do, tap all creatures your opponents control, then put a stun counter on each of those creatures. (If a permanent with a stun counter would become untapped, remove one from it instead.) Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

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.

Kicker {3} Indestructible When Skyclave Relic enters the battlefield, if it was kicked, create two tapped tokens that are copies of Skyclave Relic. {T}: Add one mana of any color.

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

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle. When Solemn Simulacrum dies, you may draw a card.

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.

When Brinelin, the Moon Kraken enters the battlefield or whenever you cast a spell with mana value 6 or greater, you may return target nonland permanent to its owner's hand. Partner (You can have two commanders if both have partner.)

Counter target spell.

Counter target noncreature spell. Its controller loses 2 life.

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.

Choose one — • Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard. • Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

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.

Affinity for tokens (This spell costs {1} less to cast for each token you control.) Whenever a token enters the battlefield under your control, tap target nonland permanent an opponent controls. It doesn't untap during its controller's next untap step.

Counter target noncreature spell.

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.

{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.

Cleave {1}{U}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.) Counter target spell [that wasn't cast from its owner's hand].

Whenever you draw a card, you may pay {1}. If you do, put a +1/+1 counter on Nadir Kraken and create a 1/1 blue Tentacle creature token.

Whenever you draw a card, put a foreshadow counter on Ominous Seas. Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token. Cycling {2} ({2}, Discard this card: Draw a card.)

{T}: Add {U} or {B}. {U}{B}, {T}, Sacrifice Dimir Cluestone: Draw a card.

{T}: Add {U} or {B}. {U}{B}: Dimir Keyrune becomes a 2/2 blue and black Horror artifact creature until end of turn and can't be blocked this turn.

Each player mills two cards. Then you put a creature card from a graveyard onto the battlefield under your control.

Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Harbor Serpent can't attack unless there are five or more Islands on the battlefield.

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

When Kiora's Dambreaker enters the battlefield, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Whenever Nemesis of Reason attacks, defending player mills ten cards.

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.) Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Flash This spell can't be countered. Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Return three lands you control to their owner's hand: Return Pearl Lake Ancient to its owner's hand.

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

{2}{U}, {T}: Put target creature on the bottom of its owner's library. That creature's controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield and the rest on the bottom of their library in any order. Activate only as a sorcery.

{4}, {T}: You may put a creature card from your hand onto the battlefield.

Trample, ward {2} At the beginning of each combat, if Reservoir Kraken is untapped, any opponent may tap an untapped creature they control. If they do, tap Reservoir Kraken and create a 1/1 blue Fish creature token with "This creature can't be blocked."

River Serpent can't attack unless there are five or more cards in your graveyard. Cycling {U} ({U}, Discard this card: Draw a card.)

Exploit (When this creature enters the battlefield, you may sacrifice a creature.) When Rot-Tide Gargantua exploits a creature, each opponent sacrifices a creature.

Indestructible As long as your devotion to blue is less than five, Thassa isn't a creature. At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control. {3}{U}: Tap another target creature.

The Watcher in the Water enters the battlefield tapped with nine stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.) Whenever you draw a card during an opponent's turn, create a 1/1 blue Tentacle creature token. Whenever a Tentacle you control dies, untap up to one target Kraken and put a stun counter on up to one target nonland permanent.