Karfell Harbinger

{T}: Add {U}. Spend this mana only to foretell a card from your hand or cast an instant or sorcery spell.

Archmage's Newt

Whenever Archmage's Newt deals combat damage to a player, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. That card gains flashback {0} until end of turn instead if Archmage's Newt is saddled. (You may cast that card from your graveyard for its flashback cost. Then exile it.)
Saddle 3

Essence Scatter

Make Disappear

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Counter target spell unless its controller pays {2}.

Saruman's Trickery

Counter target spell.
Amass Orcs 1. (Put a +1/+1 counter 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.)

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Exclude

Counter target creature spell.
Draw a card.

Geometric Nexus

Whenever a player casts an instant or sorcery spell, put a number of charge counters on Geometric Nexus equal to that spell's mana value.
{6}, {T}, Remove all charge counters from Geometric Nexus: Create a 0/0 green and blue Fractal creature token. Put X +1/+1 counters on it, where X is the number of charge counters removed this way.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

Mesmeric Glare

Counter target spell with mana value 3 or less. (Then exile this card. You may cast the creature later from exile.)

Hypnotic Sprite

Hypnotic Sprite // Mesmeric Glare

Unblinking Observer

{T}: Add {U}. Spend this mana only to pay a disturb cost or cast an instant or sorcery spell.

Wavebreak Hippocamp

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

Ice Out

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
This spell costs {1} less to cast if it's bargained.
Counter target spell.

Counterspell

Lose Focus

Replicate {U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Counter target spell unless its controller pays {2}.

Rewind

Counter target spell. Untap up to four lands.

Island

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.)

Traumatic Visions

Counter target spell.
Basic landcycling {1}{U} ({1}{U}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Out of Air

This spell costs {2} less to cast if it targets a creature spell.
Counter target spell.

Twist Reality

Choose one —
• Counter target spell.
• Manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Volshe Tideturner

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

Riptide Laboratory

{T}: Add {C}.
{1}{U}, {T}: Return target Wizard you control to its owner's hand.

Anticognition

Counter target creature or planeswalker spell unless its controller pays {2}. If an opponent has eight or more cards in their graveyard, instead counter that spell, then scry 2.

Bag of Holding

Whenever you discard a card, exile that card from your graveyard.
{2}, {T}: Draw a card, then discard a card.
{4}, {T}, Sacrifice Bag of Holding: Return all cards exiled with Bag of Holding to their owner's hand.

Don't Make a Sound

Counter target spell unless its controller pays {2}. If they do, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Neutralize

Counter target spell.
Cycling {2} ({2}, Discard this card: Draw a card.)

Glorious Gale

Counter target creature spell. If it was a legendary spell, the Ring tempts you.

Lonely Sandbar

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

Callous Dismissal

Return target nonland permanent to its owner's hand.
Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)

Castle Vantress

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

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}.

Sinister Sabotage

Counter target spell.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Refute

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

Geyser Drake

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

You Find the Villains' Lair

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

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.

Rise from the Tides

Create a tapped 2/2 black Zombie creature token for each instant and sorcery card in your graveyard.

Elementalist Adept

Flash (You may cast this spell any time you could cast an instant.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Wishing Well

{T}: Put a coin counter on Wishing Well. When you do, you may cast target instant or sorcery card with mana value equal to the number of coin counters on Wishing Well from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead. Activate only as a sorcery.

Ertai's Scorn

This spell costs {U} less to cast if an opponent cast two or more spells this turn.
Counter target spell.

Dissipate

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Negate

Bane's Contingency

Counter target spell. If that spell targets a commander you control, instead counter that spell, scry 2, then draw a card.

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Soul Read

Choose one —
• Counter target spell unless its controller pays {4}.
• Draw two cards.

Brain in a Jar

{1}, {T}: Put a charge counter on Brain in a Jar, then you may cast an instant or sorcery spell with mana value equal to the number of charge counters on Brain in a Jar from your hand without paying its mana cost.
{3}, {T}, Remove X charge counters from Brain in a Jar: Scry X.

Cancel

Mocking Sprite

Flying
Instant and sorcery spells you cast cost {1} less to cast.

Saw It Coming

Counter target spell.
Foretell {1}{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.)

Mischievous Mystic

Flying
Whenever you draw your second card each turn, create a 1/1 blue Faerie creature token with flying.

Summoner's Bane

Counter target creature spell. Create a 2/2 blue Illusion creature token.

Dazzling Denial

Counter target spell unless its controller pays {2}. If you control a Bird, counter that spell unless its controller pays {4} instead.

Jhessian Thief

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever Jhessian Thief deals combat damage to a player, draw a card.

Naiad of Hidden Coves

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

Supreme Will

Choose one —
• Counter target spell unless its controller pays {3}.
• Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

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

Everdream

Draw a card.
Splice onto instant or sorcery {2}{U} (As you cast an instant or sorcery spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Treason of Isengard

Put up to one target instant or sorcery card from your graveyard on top of your library.
Amass Orcs 2. (To 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.)

Murmuring Mystic

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

Calculated Dismissal

Counter target spell unless its controller pays {3}.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, scry 2. (To 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.)

Pelargir Survivor

{T}: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell.
{5}{U}, {T}: Target player mills three cards. (They put the top three cards of their library into their graveyard.)

Defabricate

Choose one —
• Counter target artifact or enchantment spell. If a spell is countered this way, exile it instead of putting it into its owner's graveyard.
• Counter target activated or triggered ability.

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.)