Mana Leak

Counter target spell unless its controller pays {3}.

Have

Island

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Adeliz, the Cinder Wind

Flying, haste
Whenever you cast an instant or sorcery spell, Wizards you control get +1/+1 until end of turn.

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Wizard's Lightning

This spell costs {2} less to cast if you control a Wizard.
Wizard's Lightning deals 3 damage to any target.

Arcane Infusion

Look at the top four cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
Flashback {3}{U}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Thunderbolt

Choose one —
• Thunderbolt deals 3 damage to target player or planeswalker.
• Thunderbolt deals 4 damage to target creature with flying.

Seize the Storm

Create a red Elemental creature token with trample and "This creature's power and toughness are each equal to the number of instant and sorcery cards in your graveyard plus the number of cards with flashback you own in exile."
Flashback {6}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Blow Off Steam

Blow Off Steam deals 1 damage to any target. (Then exile this card. You may cast the creature later from exile.)

Frolicking Familiar

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

Frolicking Familiar // Blow Off Steam

Negate

Aegar, the Freezing Flame

Whenever a creature or planeswalker an opponent controls is dealt excess damage, if a Giant, Wizard, or spell you controlled dealt damage to it this turn, draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Anticipate

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Twinferno

Choose one —
• When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
• Target creature you control gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Mountain

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.

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Prismari Campus

Prismari Campus enters tapped.
{T}: Add {U} or {R}.
{4}, {T}: Scry 1.

Impulse

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.

Stormcatch Mentor

Haste
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Balmor, Battlemage Captain

Flying
Whenever you cast an instant or sorcery spell, creatures you control get +1/+0 and gain trample until end of turn.

Windrider Wizard

Flying
Whenever you cast an instant, sorcery, or Wizard spell, you may draw a card. If you do, discard a card.