Theros

Horizon Scholar

Horizon Scholar {5}{U}

Creature - Sphinx
Flying
When Horizon Scholar enters the battlefield, scry 2.
4/4
Lost in a Labyrinth

Lost in a Labyrinth {U}

Instant
Target creature gets -3/-0 until end of turn. Scry 1.
Even those who leave the labyrinth never escape it, forever dreaming of their time trapped within.
Master of Waves

Master of Waves {3}{U}

Creature - Merfolk Wizard
Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters the battlefield, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue.
2/1
Meletis Charlatan

Meletis Charlatan {2}{U}

Creature - Human Wizard
{2}{U}, {T}: The controller of target instant or sorcery spell copies it. That player may choose new targets for the copy.
"Every object has an echo in the Aether beyond the world. Every idea has a shadow that can be brought to light."
2/3
Mnemonic Wall

Mnemonic Wall {4}{U}

Creature - Wall
Defender
When Mnemonic Wall enters the battlefield, you may return target instant or sorcery card from your graveyard to your hand.
"It augments anamnesis. What is so confusing about that?"
—Perisophia the philosopher
0/4
Nimbus Naiad

Nimbus Naiad {2}{U}

Enchantment Creature - Nymph
Bestow {4}{U}
Flying
Enchanted creature gets +2/+2 and has flying.
2/2
Omenspeaker

Omenspeaker {1}{U}

Creature - Human Wizard
When Omenspeaker enters the battlefield, scry 2.
Her prophecies amaze her even as she speaks them.
1/3
Ordeal of Thassa

Ordeal of Thassa {1}{U}

Enchantment - Aura
Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Thassa.
When you sacrifice Ordeal of Thassa, draw two cards.
Prescient Chimera

Prescient Chimera {3}{U}{U}

Creature - Chimera
Flying
Whenever you cast an instant or sorcery spell, scry 1.
3/4
Prognostic Sphinx

Prognostic Sphinx {3}{U}{U}

Creature - Sphinx
Flying
Discard a card: Prognostic Sphinx gains hexproof until end of turn. Tap it.
Whenever Prognostic Sphinx attacks, scry 3.
3/5
Sea God's Revenge

Sea God's Revenge {5}{U}

Sorcery
Return up to three target creatures your opponents control to their owners' hands. Scry 1.
"What has neither mouth nor throat, yet swallows captain, crew, and boat?"
—Sphinx's riddle
Sealock Monster

Sealock Monster {3}{U}{U}

Creature - Octopus
Sealock Monster can't attack unless defending player controls an Island.
{5}{U}{U}: Monstrosity 3.
When Sealock Monster becomes monstrous, target land becomes an Island in addition to its other types.
5/5
Shipbreaker Kraken

Shipbreaker Kraken {4}{U}{U}

Creature - Kraken
{6}{U}{U}: Monstrosity 4.
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.
6/6
Stymied Hopes

Stymied Hopes {1}{U}

Instant
Counter target spell unless its controller pays {1}. Scry 1.
When a god's will is against you, the day never ends well.
Swan Song

Swan Song {U}

Instant
Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.
"The most enlightened mages create beauty from violence."
—Medomai the Ageless
Thassa, God of the Sea

Thassa, God of the Sea {2}{U}

Legendary Enchantment Creature - God
Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.
5/5
Thassa's Bounty

Thassa's Bounty {5}{U}

Sorcery
Draw three cards. Target player mills three cards.
"Was this gift cast adrift for any to find, or did Thassa guide the currents to bring it to me alone?"
—Kenessos, priest of Thassa
Thassa's Emissary

Thassa's Emissary {3}{U}

Enchantment Creature - Crab
Bestow {5}{U}
Whenever Thassa's Emissary or enchanted creature deals combat damage to a player, draw a card.
Enchanted creature gets +3/+3.
3/3
Triton Fortune Hunter

Triton Fortune Hunter {2}{U}

Creature - Merfolk Soldier
Heroic — Whenever you cast a spell that targets Triton Fortune Hunter, draw a card.
"Thassa has blessed me with power and insight. I am careful not to disappoint her."
2/2
Triton Shorethief

Triton Shorethief {U}

Creature - Merfolk Rogue
At sunrise, the Champion and her companions awoke to find their supplies gone and Brygus, their sentry, dead. Carefully arranged piles of ornamental shells gave a clear warning: go no further.
—The Theriad
1/2
Triton Tactics

Triton Tactics {U}

Instant
Up to two target creatures each get +0/+3 until end of turn. Untap those creatures. At this turn's next end of combat, tap each creature that was blocked by one of those creatures this turn and it doesn't untap during its controller's next untap step.
Vaporkin

Vaporkin {1}{U}

Creature - Elemental
Flying
Vaporkin can block only creatures with flying.
"Mists are carefree. They drift where they will, unencumbered by rocks and river beds."
—Thrasios, triton hero
2/1
Voyage's End

Voyage's End {1}{U}

Instant
Return target creature to its owner's hand. Scry 1.
Philosophers say those lost at sea ascended to a more perfect realm. Sailors say they drowned.
Wavecrash Triton

Wavecrash Triton {2}{U}

Creature - Merfolk Wizard
Heroic — Whenever you cast a spell that targets Wavecrash Triton, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
1/4
Abhorrent Overlord

Abhorrent Overlord {5}{B}{B}

Creature - Demon
Flying
When Abhorrent Overlord enters the battlefield, create a number of 1/1 black Harpy creature tokens with flying equal to your devotion to black.
At the beginning of your upkeep, sacrifice a creature.
6/6