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.

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.

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

Castle Vantress enters the battlefield tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

{T}: Add {C}. {1}, {T}: Put a storage counter on Dreadship Reef. {1}, Remove X storage counters from Dreadship Reef: Add X mana in any combination of {U} and/or {B}.

({T}: Add {U}.) Moonring Island enters the battlefield tapped. {U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.

{T}: Add {C}. {1}{U}{B}, {T}: Target player mills three cards.

({T}: Add {U}.)

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

{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.

{T}: Add {C}. {2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

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

{T}: Add {C}. {T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Return all nonland permanents with mana value X or less to their owners' hands.

All creatures get -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Draw cards equal to the number of cards in your hand, then discard a card for each card drawn this way. Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

{1}, {T}: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

When Fleeting Memories enters the battlefield, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.") Whenever you sacrifice a Clue, target player mills three cards.

Scry 3, then reveal the top card of your library. Draw cards equal to that card's mana value. (To scry 3, look at the top three cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

At the beginning of your upkeep, scry 1. Whenever you discard a card, each opponent mills two cards. (They put the top two cards of their library into their graveyard.)

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.)

{T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.") {T}, Sacrifice three Clues: Search your library for a card, put that card into your hand, then shuffle.

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

Choose a creature type. Return up to two creature cards of that type from your graveyard to the battlefield. If this spell was foretold, return all creature cards of that type from your graveyard to the battlefield instead. Foretell {5}{B}{B} (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.)

Each player chooses a creature type. Each player returns all creature cards of a type chosen this way from their graveyard to the battlefield.

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.

Counter target spell unless its controller pays {X}. Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Counter target spell.

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

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.

Destroy up to three target creatures with toughness X or less. If X is 10 or more, return all creature cards from your graveyard to the battlefield.

Target player mills ten cards.

Enchant creature, land, or planeswalker Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Return target creature to its owner's hand. Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

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.

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.)

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.

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

Companion — Your starting deck contains only cards with even mana values. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.) When Gyruda enters the battlefield, each player mills four cards. Put a creature card with an even mana value from among the milled cards onto the battlefield under your 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.

This spell costs {1} less to cast for each snow land you control. When Icebreaker Kraken enters the battlefield, artifacts and creatures target opponent controls don't untap during that player's next untap step. Return three snow lands you control to their owner's hand: Return Icebreaker Kraken to its owner's hand.

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.)

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 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 Nemesis of Reason attacks, defending player mills ten cards.

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.

Sea Monster can't attack unless defending player controls an Island.

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.

Krakens, Leviathans, Octopuses, and Serpents you control can't be blocked except by Krakens, Leviathans, Octopuses, and Serpents.

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.

Whenever a Kraken, Leviathan, Octopus, or Serpent you control deals combat damage to a player, create a 9/9 blue Kraken creature token.

Hexproof Lieutenant — As long as you control your commander, Stormsurge Kraken gets +2/+2 and has "Whenever Stormsurge Kraken becomes blocked, you may draw two cards."

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.

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.)

Target player draws two cards. Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Whenever another creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.") Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Enchant creature (Target a creature as you cast this. This card enters the battlefield attached to that creature.) Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)