Burst of Speed

Creatures you control gain haste until end of turn. (They can attack and {T} even if they just came under your control.)

Mana Leak

Counter target spell unless its controller pays {3}.

Izzet Signet

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Djinn Illuminatus

({U/R} can be paid with either {U} or {R}.)
Flying
Each instant and sorcery spell you cast has replicate. The replicate cost is equal to its mana cost. (When you cast it, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Mountain

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

Negate

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Pact of the Titan

Create a 4/4 red Giant creature token.
At the beginning of your next upkeep, pay {4}{R}. If you don't, you lose the game.

Jwari Ruins

Jwari Disruption

Counter target spell unless its controller pays {1}.

Jwari Disruption // Jwari Ruins

Island

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.