Nadir Kraken

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

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on this creature.
When this creature dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on this creature. (They can't be blocked as long as defending player controls an Island.)

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Sapphire Medallion

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

Merfolk Looter

Clinquant Skymage

Flying
Whenever you draw a card, put a +1/+1 counter on this creature.

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.

Wonder

Flying
As long as this card is in your graveyard and you control an Island, creatures you control have flying.

Psychosis Crawler

Psychosis Crawler's power and toughness are each equal to the number of cards in your hand.
Whenever you draw a card, each opponent loses 1 life.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Body of Knowledge

Body of Knowledge's power and toughness are each equal to the number of cards in your hand.
You have no maximum hand size.
Whenever this creature is dealt damage, draw that many cards.

Meeting of Minds

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw two cards.

Fear of Sleep Paralysis

Flying
Eerie — Whenever this creature or another enchantment you control enters and whenever you fully unlock a Room, tap up to one target creature and put a stun counter on it.
Stun counters can't be removed from permanents your opponents control. (They won't untap if they have stun counters.)

Solemn Simulacrum

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

Eaten by Piranhas

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature loses all abilities and is a black Skeleton creature with base power and toughness 1/1. (It loses all other colors, card types, and creature types.)

Triskaidekaphile

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.

Island

Refute

Counter target spell. Draw a card, then discard a card.

Grappling Kraken

Landfall — Whenever a land you control enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Geyser Drake

Flying
During turns other than yours, spells you cast cost {1} less to cast.

Floodpits Drowner

Flash
Vigilance
When this creature enters, tap target creature an opponent controls and put a stun counter on it.
{1}{U}, {T}: Shuffle this creature and target creature with a stun counter on it into their owners' libraries.

Jace's Archivist

{U}, {T}: Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Flow of Knowledge

Draw a card for each Island you control, then discard two cards.

Symmetry Matrix

Whenever a creature you control with power equal to its toughness enters, you may pay {1}. If you do, draw a card.

Drowned Rusalka

{U}, Sacrifice a creature: Discard a card, then draw a card.

Scourge of Fleets

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.

Abjure

As an additional cost to cast this spell, sacrifice a blue permanent.
Counter target spell.

Dream Fracture

Counter target spell. Its controller draws a card.
Draw a card.

Nezahal, Primal Tide

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. Return it to the battlefield tapped under its owner's control at the beginning of the next end step.

Thought Vessel

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

The Watcher in the Water

The Watcher in the Water enters 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.

Thirst for Discovery

Draw three cards. Then discard two cards unless you discard a basic land card.

Consider

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

Mind Stone

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

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Monstrosity of the Lake

When Monstrosity of the Lake enters, 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.)

Brainsurge

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

Kiora, the Rising Tide

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Mystic Confluence

Choose three. You may choose the same mode more than once.
• Counter target spell unless its controller pays {3}.
• Return target creature to its owner's hand.
• Draw a card.

Reliquary Tower

Hullbreaker Horror

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.

Perilous Research

Draw two cards, then sacrifice a permanent.

Lost in the Maze

Flash
When this enchantment enters, tap X target creatures. Put a stun counter on each of those creatures you don't control. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Tapped creatures you control have hexproof.

Counterspell

Stormsurge Kraken

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

Oneirophage

Transcendent Message

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Draw X cards.

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Spawning Kraken

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

High Tide

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

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

Brainstorm

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

Quick Study

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Arcane Denial

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.

Tolarian Winds

Discard all the cards in your hand, then draw that many cards.

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Negate

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Pull from Tomorrow

Glimmerburst

Draw two cards. Create a 1/1 white Glimmer enchantment creature token.

Ominous Seas

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

Deep-Sea Kraken

This creature 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 this card is suspended, remove a time counter from it.

Sol Ring

Ioreth of the Healing House

{T}: Untap another target permanent.
{T}: Untap two other target legendary creatures.

Keep Safe

Counter target spell that targets a permanent you control.
Draw a card.

Aetherize

Return all attacking creatures to their owner's hand.

Tromokratis

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.)

Artistic Refusal

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose one or both —
• Counter target spell.
• Draw two cards, then discard a card.