Aven Wind Mage

Flying
Whenever you cast an instant or sorcery spell, this creature gets +1/+1 until end of turn.

Counterbalance

Whenever an opponent casts a spell, you may reveal the top card of your library. If you do, counter that spell if it has the same mana value as the revealed card.

Artful Dodge

Target creature can't be blocked this turn.
Flashback {U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Frog Lizard

Extinguish

Annul

Counter target artifact or enchantment spell.

Island

Amazing Acrobatics

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

Arcane Melee

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

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Bone to Ash

Counter target creature spell.
Draw a card.

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Glen Elendra's Answer

This spell can't be countered.
Counter all spells your opponents control and all abilities your opponents control. Create a 1/1 blue and black Faerie creature token with flying for each spell and ability countered this way.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Adaptive Training Post

Whenever you cast an instant or sorcery spell, if this artifact has fewer than three charge counters on it, put a charge counter on it.
Remove three charge counters from this artifact: When you next cast an instant or sorcery spell this turn, copy it and you may choose new targets for the copy.

Counterspell

Dispel

Amulet of Safekeeping

Whenever you become the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.
Creature tokens get -1/-0.

Creature Bond

Enchant creature
When enchanted creature dies, this Aura deals damage equal to that creature's toughness to the creature's controller.

Academy Elite

This creature enters with X +1/+1 counters on it, where X is the number of instant and sorcery cards in all graveyards.
{2}{U}, Remove a +1/+1 counter from this creature: Draw a card, then discard a card.

Cancel

Jace's Sanctum

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