Scrivener

When Scrivener enters, you may return target instant card from your graveyard to your hand.

Eel Umbra

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +1/+1.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Vodalian Arcanist

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

Quick Study

Spell Burst

Buyback {3} (You may pay an additional {3} as you cast this spell. If you do, put this card into your hand as it resolves.)
Counter target spell with mana value X.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Mistfolk

{U}: Counter target spell that targets Mistfolk.

Guard Gomazoa

Defender, flying
Prevent all combat damage that would be dealt to Guard Gomazoa.

Wistful Thinking

Target player draws two cards, then discards four cards.

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Wandering Eye

Flying
Players play with their hands revealed.

Draining Whelk

Flash
Flying
When Draining Whelk enters, counter target spell. Put X +1/+1 counters on Draining Whelk, where X is that spell's mana value.

Abjure

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

Psychic Membrane

Defender (This creature can't attack.)
Whenever Psychic Membrane blocks, you may draw a card.

As Foretold

At the beginning of your upkeep, put a time counter on As Foretold.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on As Foretold.

Miscast

Counter target instant or sorcery spell unless its controller pays {3}.

War Tax

{X}{U}: This turn, creatures can't attack unless their controller pays {X} for each attacking creature they control.

Turn Aside

Counter target spell that targets a permanent you control.

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.

Flip the Switch

Counter target spell unless its controller pays {4}. Create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Shell Skulkin

{3}: Target blue creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Convolute

Counter target spell unless its controller pays {4}.

Kraken's Eye

Whenever a player casts a blue spell, you may gain 1 life.

Wavebreak Hippocamp

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

Voracious Reader

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Curious Homunculus

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.
At the beginning of your upkeep, if there are three or more instant and/or sorcery cards in your graveyard, transform Curious Homunculus.

Curious Homunculus // Voracious Reader

Dream Fracture

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

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Quiet Contemplation

Whenever you cast a noncreature spell, you may pay {1}. If you do, tap target creature an opponent controls and it doesn't untap during its controller's next untap step.

Curator of Mysteries

Flying
Whenever you cycle or discard another card, scry 1.
Cycling {U} ({U}, Discard this card: Draw a card.)

Mirrorshell Crab

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Channel — {2}{U}, Discard Mirrorshell Crab: Counter target spell or ability unless its controller pays {3}.

Counterspell

Thassa's Rebuff

Counter target spell unless its controller pays {X}, where X is your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Essence Capture

Counter target creature spell. Put a +1/+1 counter on up to one target creature you control.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

Prescient Chimera

Flying
Whenever you cast an instant or sorcery spell, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Negate

Baral, Chief of Compliance

Instant and sorcery spells you cast cost {1} less to cast.
Whenever a spell or ability you control counters a spell, you may draw a card. If you do, discard a card.

Split the Party

Choose target player. Return half the creatures they control to their owner's hand, rounded up.

Phantom Interference

Spree (Choose one or more additional costs.)
+ {3} — Create a 2/2 white Spirit creature token with flying.
+ {1} — Counter target spell unless its controller pays {2}.

Misstep

Creatures target player controls don't untap during that player's next untap step.

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Saruman the White

Ward {2}
Whenever you cast your second spell each turn, amass Orcs 2. (Put two +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Fold into Aether

Counter target spell. If that spell is countered this way, its controller may put a creature card from their hand onto the battlefield.

Fervent Denial

Counter target spell.
Flashback {5}{U}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Sinister Concierge

When Sinister Concierge dies, you may exile it and put three time counters on it. If you do, exile up to one target creature and put three time counters on it. Each card exiled this way that doesn't have suspend gains suspend. (For each card with suspend, its owner removes a time counter from it at the beginning of their upkeep. When the last is removed, they may cast it without paying its mana cost. Those creature spells have haste.)

Diplomatic Escort

{U}, {T}, Discard a card: Counter target spell or ability that targets a creature.

Energy Flux

All artifacts have "At the beginning of your upkeep, sacrifice this artifact unless you pay {2}."

Force Void

Counter target spell unless its controller pays {1}.
Draw a card at the beginning of the next turn's upkeep.

Harbinger of the Seas

Island

Condescend

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 and the rest on top in any order.)

Neurok Stealthsuit

Equipped creature has shroud. (It can't be the target of spells or abilities.)
{U}{U}: Attach Neurok Stealthsuit to target creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Drawn from Dreams

Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in a random order.

Dismal Failure

Counter target spell. Its controller discards a card.

Infiltrate

Target creature can't be blocked this turn.

High Seas

Red creature spells and green creature spells cost {1} more to cast.

Geyser Drake

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

Diplomatic Immunity

Enchant creature
Shroud (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creature has shroud.

Cancel

Murmuring Mystic

Whenever you cast an instant or sorcery spell, create a 1/1 blue Bird Illusion creature token with flying.

Annul

Counter target artifact or enchantment spell.

Daring Apprentice

{T}, Sacrifice Daring Apprentice: Counter target spell.

Mnemonic Wall

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Magus of the Future

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

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.

Victory Chimes

Untap Victory Chimes during each other player's untap step.
{T}: A player of your choice adds {C}.