Draining Whelk

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

Artistic Refusal

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Choose one or both —
• Counter target spell.
• Draw two cards, then discard a card.

Lost in the Mist

Counter target spell. Return target permanent to its owner's hand.

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.

Out of Air

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

Disruptive Pitmage

{T}: Counter target spell unless its controller pays {1}.
Morph {U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Silumgar Sorcerer

Flash (You may cast this spell any time you could cast an instant.)
Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, counter target creature spell.

Fervent Denial

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

Mocking Sprite

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

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Voidmage Husher

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

Discombobulate

Counter target spell. Look at the top four cards of your library, then put them back in any order.

Sky Diamond

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

Cognivore

Flying
Cognivore's power and toughness are each equal to the number of instant cards in all graveyards.

Sunken Field

Enchant land
Enchanted land has "{T}: Counter target spell unless its controller pays {1}."

Martyr of Frost

{2}, Reveal X blue cards from your hand, Sacrifice this creature: Counter target spell unless its controller pays {X}.

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.)

Hall of Oracles

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{T}: Put a +1/+1 counter on target creature. Activate only as a sorcery and only if you've cast an instant or sorcery spell this turn.

Font of Magic

Instant and sorcery spells you cast cost {1} less to cast for each time you've cast a commander from the command zone this game.

Soratami Savant

Flying
{3}, Return a land you control to its owner's hand: Counter target spell unless its controller pays {3}.

Bone to Ash

Counter target creature spell.
Draw a card.

Spiketail Drakeling

Flying
Sacrifice this creature: Counter target spell unless its controller pays {2}.

Shimmering Glasskite

Flying
Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability.

Jetting Glasskite

Stronghold Machinist

{U}{U}, {T}, Discard a card: Counter target noncreature spell.

Benevolent Geist

Flying
Noncreature spells you control can't be countered.
If Benevolent Geist would be put into a graveyard from anywhere, exile it instead.

Malevolent Hermit

{U}, Sacrifice this creature: Counter target noncreature spell unless its controller pays {3}.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Malevolent Hermit // Benevolent Geist

Exclude

Diversion Unit

Flying
{U}, Sacrifice this creature: Counter target instant or sorcery spell unless its controller pays {3}.

Hisoka, Minamo Sensei

{2}{U}, Discard a card: Counter target spell if it has the same mana value as the discarded card.

Spell Snuff

Counter target spell.
Fateful hour — If you have 5 or less life, draw a card.

Voracious Greatshark

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, counter target artifact or creature spell.

Sinister Sabotage

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

Contradict

Disciple of the Ring

{1}, Exile an instant or sorcery card from your graveyard: Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• This creature gets +1/+1 until end of turn.
• Tap target creature.
• Untap target creature.

Lay Bare

Counter target spell. Look at its controller's hand.

Overcharged Amalgam

Flash
Flying
Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, counter target spell, activated ability, or triggered ability.

Vodalian Mage

{U}, {T}: Counter target spell unless its controller pays {1}.

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.

Glamdring

Equipped creature has first strike and gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever equipped creature deals combat damage to a player, you may cast an instant or sorcery spell from your hand with mana value less than or equal to that damage without paying its mana cost.
Equip {3}

Scatter Arc

Counter target noncreature spell.
Draw a card.

Spellgyre

Choose one —
• Counter target spell.
• Surveil 2, then draw two cards. (To 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.)

Psychic Barrier

Counter target creature spell. Its controller loses 1 life.

Jace's Sanctum

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, scry 1.

Island

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Cancel

Essence Scatter

Countermand

Counter target spell. Its controller mills four cards.

Arcane Melee

Instant and sorcery spells cost {2} less to cast.

Cerulean Drake

Flying
Protection from red (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything red.)
Sacrifice this creature: Counter target spell that targets you.

Disruptive Student

{T}: Counter target spell unless its controller pays {1}.

Memory Drain

Sentinel Tower

Whenever an instant or sorcery spell is cast during your turn, this artifact deals damage to any target equal to 1 plus the number of instant and sorcery spells cast before that spell this turn.

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

Dissipate

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

Siren Stormtamer

Flying
{U}, Sacrifice this creature: Counter target spell or ability that targets you or a creature you control.

Essence Capture

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

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Neutralize

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

Failed Inspection

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

Forceful Denial

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Counter target spell.

Hope-Ender Coatl

Devoid (This card has no color.)
Flash
When you cast this spell, counter target spell an opponent controls unless they pay {1}.
Flying