Censor

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

Ertai, Wizard Adept

Amazing Acrobatics

Choose one or both —
• Counter target spell.
• Tap one or two target creatures.

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}.

Quench

Counter target spell unless its controller pays {2}.

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.)

Abjure

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

Counterspell

Declaration of Naught

As this enchantment enters, choose a card name.
{U}: Counter target spell with the chosen name.

Mana Leak

Counter target spell unless its controller pays {3}.

Force Spike

Counter target spell unless its controller pays {1}.

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.

Clash of Wills

Counter target spell unless its controller pays {X}.

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.)

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.