Precognition Field

You may look at the top card of your library any time.
You may cast instant and sorcery spells from the top of your library.
{3}: Exile the top card of your library.

Sentinel of the Pearl Trident

Flash
When Sentinel of the Pearl Trident enters, you may exile target historic permanent you control. If you do, return that card to the battlefield under its owner's control at the beginning of the next end step. (Artifacts, legendaries, and Sagas are historic.)

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control Time of Ice.
III — Return all tapped creatures to their owners' hands.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Bident of Thassa

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.

Flood of Recollection

Return target instant or sorcery card from your graveyard to your hand. Exile Flood of Recollection.

Mist-Cloaked Herald

Riverwise Augur

When Riverwise Augur enters, draw three cards, then put two cards from your hand on top of your library in any order.

Traveler's Amulet

{1}, Sacrifice Traveler's Amulet: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Wake Thrasher

Whenever a permanent you control becomes untapped, Wake Thrasher gets +1/+1 until end of turn.

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

One With the Wind

Enchant creature
Enchanted creature gets +2/+2 and has flying.

River Sneak

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

Shaper Apprentice

Shaper Apprentice has flying as long as you control another Merfolk.

Watertrap Weaver

When Watertrap Weaver enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Clone Legion

For each creature target player controls, create a token that's a copy of that creature.

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Desert of the Mindful

Desert of the Mindful enters tapped.
{T}: Add {U}.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

Kefnet's Monument

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.

Deep-Sea Kraken

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.

Aethersquall Ancient

Flying
At the beginning of your upkeep, you get {E}{E}{E} (three energy counters).
Pay eight {E}: Return all other creatures to their owners' hands. Activate only as a sorcery.

Serum Visions

Elder Deep-Fiend

Flash
Emerge {5}{U}{U} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.)
When you cast this spell, tap up to four target permanents.

Blustersquall

Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Skyline Cascade

Skyline Cascade enters tapped.
When Skyline Cascade enters, target creature an opponent controls doesn't untap during its controller's next untap step.
{T}: Add {U}.

Scourge of Fleets

When Scourge of Fleets 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.

Breaching Leviathan

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

Icy Blast

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.

Negate

Stormtide Leviathan

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.

Staff of the Mind Magus

Whenever you cast a blue spell or an Island you control enters, you gain 1 life.

Polymorphous Rush

Strive — This spell costs {1}{U} more to cast for each target beyond the first.
Choose a creature on the battlefield. Any number of target creatures you control each become a copy of that creature until end of turn.

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.)

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Illusionist's Gambit

Cast this spell only during the declare blockers step on an opponent's turn.
Remove all attacking creatures from combat and untap them. After this phase, there is an additional combat phase. Each of those creatures attacks that combat if able. They can't attack you or planeswalkers you control that combat.

Sol Ring

Shipbreaker Kraken

{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.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Archaeomancer

When Archaeomancer enters, return target instant or sorcery card from your graveyard to your hand.

Clone

You may have Clone enter as a copy of any creature on the battlefield.

Colossal Whale

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Colossal Whale attacks, you may exile target creature defending player controls until Colossal Whale leaves the battlefield. (That creature returns under its owner's control.)

Jace's Mindseeker

Flying
When Jace's Mindseeker enters, target opponent mills five cards. You may cast an instant or sorcery spell from among them without paying its mana cost.

Journeyer's Kite

{3}, {T}: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

Levitation

Quest for Ula's Temple

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.

Ponder

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

Kederekt Leviathan

When Kederekt Leviathan enters, return all other nonland permanents to their owners' hands.
Unearth {6}{U} ({6}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Tidal Kraken

Time Stop

End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Shrouded Serpent

Whenever Shrouded Serpent attacks, defending player may pay {4}. If that player doesn't, Shrouded Serpent can't be blocked this turn.

Frantic Search

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

High Tide

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

Brainstorm

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

Vodalian Arcanist

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.

Slinn Voda, the Rising Deep

Kicker {1}{U} (You may pay an additional {1}{U} as you cast this spell.)
When Slinn Voda, the Rising Deep enters, if it was kicked, return all creatures to their owners' hands except for Merfolk, Krakens, Leviathans, Octopuses, and Serpents.

Zhalfirin Void

When Zhalfirin Void enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {C}.

Memorial to Genius

Memorial to Genius enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Island

Switcheroo

Exchange control of two target creatures.

Sift

Aether Tunnel

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked.

Kraken Hatchling

Saltwater Stalwart

Whenever Saltwater Stalwart deals damage to an opponent, target player draws a card.

Game Plan

Assist (Another player can pay up to {5} of this spell's cost.)
Each player shuffles their hand and graveyard into their library, then draws seven cards. Exile Game Plan.

Lonely Sandbar

Lonely Sandbar enters tapped.
{T}: Add {U}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Saheeli's Artistry

Choose one or both —
• Create a token that's a copy of target artifact.
• Create a token that's a copy of target creature, except it's an artifact in addition to its other types.

Inkwell Leviathan

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.)

Geode Golem

Trample
Whenever Geode Golem deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Rogue's Passage

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

Mesmerizing Benthid

When Mesmerizing Benthid enters, create two 0/2 blue Illusion creature tokens with "Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step."
Mesmerizing Benthid has hexproof as long as you control an Illusion.

Augur of Bolas

When Augur of Bolas enters, look at the top three cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Silent Submersible

Whenever Silent Submersible deals combat damage to a player or planeswalker, draw a card.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

The Immortal Sun

Players can't activate planeswalkers' loyalty abilities.
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.
Creatures you control get +1/+1.

River's Rebuke

Return all nonland permanents target player controls to their owner's hand.

Reliquary Tower

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

Thought Vessel

Whelming Wave

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

Scroll Thief

Whenever Scroll Thief deals combat damage to a player, draw a card.

Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Memory Drain

Serpent of Yawning Depths

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

Nadir Kraken

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.

Shoal Kraken

Constellation — Whenever an enchantment you control enters, you may draw a card. If you do, discard a card.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Halimar Depths

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}.

Tolarian Kraken

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

Hedron Archive

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

Unstable Obelisk

{T}: Add {C}.
{7}, {T}, Sacrifice Unstable Obelisk: Destroy target permanent.

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Tamiyo's Journal

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.

Octopus Umbra

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Retreat to Coralhelm

Landfall — Whenever a land you control enters, choose one —
• You may tap or untap target creature.
• Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Lorthos, the Tidemaker

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.

Dreamstone Hedron

{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.

Explorer's Scope

Whenever equipped creature attacks, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)