Thassa, Deep-Dwelling

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.

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

Solve the Equation

Search your library for an instant or sorcery card, reveal it, put it into your hand, then shuffle.

Nevermaker

Flying
When this creature leaves the battlefield, put target nonland permanent on top of its owner's library.
Evoke {3}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Artful Dodge

Target creature can't be blocked this turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Prodigal Sorcerer

{T}: This creature deals 1 damage to any target.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

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.

Tribute Mage

When this creature enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Thought Vessel

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

Barrin, Tolarian Archmage

When Barrin enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Sower of Temptation

Flying
When this creature enters, gain control of target creature for as long as this creature remains on the battlefield.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Arcane Flight

Enchant creature
Enchanted creature gets +1/+1 and has flying.

Watcher for Tomorrow

Hideaway 4 (When this creature enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This creature enters tapped.
When this creature leaves the battlefield, put the exiled card into its owner's hand.

Sludge Monster

Whenever this creature enters or attacks, put a slime counter on up to one other target creature.
Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

Aether Adept

When this creature enters, return target creature to its owner's hand.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Negate

Thassa's Oracle

When this creature enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Brainstorm

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

Aetherize

Return all attacking creatures to their owner's hand.

Acquisition Octopus

Whenever this creature 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.)

Giant Octopus

High Tide

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

Aegis Turtle

Exclusion Mage

When this creature enters, return target creature an opponent controls to its owner's hand.

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Aetherspouts

For each attacking creature, its owner puts it on their choice of the top or bottom of their library.

Sea Gate Oracle

When this creature enters, look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

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.

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.

Brinebarrow Intruder

Flash
When this creature enters, target creature an opponent controls gets -2/-0 until end of turn.

Flood of Tears

Return all nonland permanents to their owners' hands. If you return four or more nontoken permanents you control this way, you may put a permanent card from your hand onto the battlefield.

Merchant of Secrets

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Archaeomancer

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

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Fblthp, the Lost

When Fblthp enters, draw a card. If it entered from your library or was cast from your library, draw two cards instead.
When Fblthp becomes the target of a spell, shuffle Fblthp into its owner's library.

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (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.)

Apprentice Sorcerer

{T}: This creature deals 1 damage to any target. Activate only during your turn, before attackers are declared.

Academy Drake

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Flying
If this creature was kicked, it enters with two +1/+1 counters on it.

Academy Journeymage

This spell costs {1} less to cast if you control a Wizard.
When this creature enters, return target creature an opponent controls to its owner's hand.

Island

Cryptic Serpent

This spell costs {1} less to cast for each instant and sorcery card in your graveyard.

Shrouded Serpent

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

Ponder

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

Castle Vantress

This land enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Clutch of Currents

Return target creature to its owner's hand.
Awaken 3—{4}{U} (If you cast this spell for {4}{U}, also put three +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Step Through

Return two target creatures to their owners' hands.
Wizardcycling {2} ({2}, Discard this card: Search your library for a Wizard card, reveal it, put it into your hand, then shuffle.)

Whelming Wave

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

Counterspell

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control this creature.

Arcane Savant

Before you shuffle your deck to start the game, you may reveal this card from your deck and exile an instant or sorcery card you drafted that isn't in your deck.
When this creature enters, copy a card you exiled with cards named Arcane Savant. You may cast the copy without paying its mana cost.

Mulldrifter

Flying
When this creature enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Engulf the Shore

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

Scrapdiver Serpent

This creature can't be blocked as long as defending player controls an artifact.

Leyline of Anticipation

If this card is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Cloudkin Seer

Flying
When this creature enters, draw a card.

Dragon Turtle

Flash
Drag Below — When this creature enters, tap it and up to one target creature an opponent controls. They don't untap during their controllers' next untap steps.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on this artifact.
At the beginning of each upkeep, put an hour counter on this artifact.
When the twelfth hour counter is put on this artifact, shuffle your hand and graveyard into your library, then draw seven cards. Exile this artifact.

Evacuation

Return all creatures to their owners' hands.

Time Warp

Target player takes an extra turn after this one.

Sol Ring

Mind Flayer

Dominate Monster — When this creature enters, gain control of target creature for as long as you control this creature.