Soratami Savant

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

Logic Knot

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Counter target spell unless its controller pays {X}.

Change the Equation

Choose one —
• Counter target spell with mana value 2 or less.
• Counter target red or green spell with mana value 6 or less.

Thoughtbind

Counter target spell with mana value 4 or less.

Mana Leak

Counter target spell unless its controller pays {3}.

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.)

Liquify

Counter target spell with mana value 3 or less. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Soul Read

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

Dissipate

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

Hydromorph Gull

Flying
{U}, Sacrifice Hydromorph Gull: Counter target spell that targets a creature you control.

Spiketail Hatchling

Flying (This creature can't be blocked except by creatures with flying or reach.)
Sacrifice Spiketail Hatchling: Counter target spell unless its controller pays {1}.

Cancel

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.

Outwit

Counter target spell that targets a player.

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

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.

Spell Snip

Counter target spell unless its controller pays {1}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Diplomatic Escort

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

Minor Misstep

Counter target spell with mana value 1 or less.

Spiketail Drake

Flying
Sacrifice Spiketail Drake: Counter target spell unless its controller pays {3}.

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}.

Island

Decree of Silence

Whenever an opponent casts a spell, counter that spell and put a depletion counter on Decree of Silence. If there are three or more depletion counters on Decree of Silence, sacrifice it.
Cycling {4}{U}{U} ({4}{U}{U}, Discard this card: Draw a card.)
When you cycle Decree of Silence, you may counter target spell.

Lilting Refrain

At the beginning of your upkeep, you may put a verse counter on Lilting Refrain.
Sacrifice Lilting Refrain: Counter target spell unless its controller pays {X}, where X is the number of verse counters on Lilting Refrain.

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.

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}.

Mistfolk

{U}: Counter target spell that targets Mistfolk.

Daring Apprentice

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

Broken Concentration

Counter target spell.
Madness {3}{U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Hisoka, Minamo Sensei

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

Brine Seer

{2}{U}, {T}: Reveal any number of blue cards in your hand. Counter target spell unless its controller pays {1} for each card revealed this way.

Hall of Storm Giants

If you control two or more other lands, Hall of Storm Giants enters tapped.
{T}: Add {U}.
{5}{U}: Until end of turn, Hall of Storm Giants becomes a 7/7 blue Giant creature with ward {3}. It's still a land. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Confounding Riddle

Choose one —
• Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.
• Counter target spell unless its controller pays {4}.

Runeboggle

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

Declaration of Naught

As Declaration of Naught enters, choose a card name.
{U}: Counter target spell with the chosen name.

Spell Contortion

Multikicker {1}{U} (You may pay an additional {1}{U} any number of times as you cast this spell.)
Counter target spell unless its controller pays {2}. Draw a card for each time Spell Contortion was kicked.

Ghost-Lit Warder

{3}{U}, {T}: Counter target spell unless its controller pays {2}.
Channel — {3}{U}, Discard Ghost-Lit Warder: Counter target spell unless its controller pays {4}.

Disruptive Student

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

Vodalian Mage

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

Sol Ring

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Kheru Spellsnatcher

Morph {4}{U}{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.)
When Kheru Spellsnatcher is turned face up, counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may cast that card without paying its mana cost for as long as it remains exiled.

Overcharged Amalgam

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

Turn Aside

Counter target spell that targets a permanent you control.

Hydromorph Guardian

{U}, Sacrifice Hydromorph Guardian: Counter target spell that targets a creature you control.

Rakshasa's Disdain

Counter target spell unless its controller pays {1} for each card in your graveyard.

Mindreaver

Heroic — Whenever you cast a spell that targets Mindreaver, exile the top three cards of target player's library.
{U}{U}, Sacrifice Mindreaver: Counter target spell with the same name as a card exiled with Mindreaver.

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.)

Frightful Delusion

Counter target spell unless its controller pays {1}. That player discards a card.

Spiketail Drakeling

Flying
Sacrifice Spiketail Drakeling: Counter target spell unless its controller pays {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}.

Wizard Replica

Flying
{U}, Sacrifice Wizard Replica: Counter target spell unless its controller pays {2}.

Censor

Counter target spell unless its controller pays {1}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Martyr of Frost

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

Bring the Ending

Counter target spell unless its controller pays {2}.
Corrupted — Counter that spell instead if its controller has three or more poison counters.

Silumgar Spell-Eater

Megamorph {4}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Silumgar Spell-Eater is turned face up, counter target spell unless its controller pays {3}.

Sunken Field

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

Countermand

Counter target spell. Its controller mills four cards.

Circular Logic

Counter target spell unless its controller pays {1} for each card in your graveyard.
Madness {U} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Dream Fracture

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

Cerulean Drake

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

Bane's Contingency

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

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.

Countervailing Winds

Counter target spell unless its controller pays {1} for each card in your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)

Keep Safe

Counter target spell that targets a permanent you control.
Draw a card.

Hindering Touch

Counter target spell unless its controller pays {2}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Lullmage Mentor

Whenever a spell or ability you control counters a spell, you may create a 1/1 blue Merfolk creature token.
Tap seven untapped Merfolk you control: Counter target spell.