Sanguinary Mage

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Thorned Moloch

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Thorned Moloch has first strike as long as it's attacking.

Mountain

Lightning Strike

Lightning Strike deals 3 damage to any target.

Pharagax Giant

Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Pharagax Giant enters, if tribute wasn't paid, Pharagax Giant deals 5 damage to each opponent.

Goblin Wizardry

Create two 1/1 red Goblin Wizard creature tokens with prowess. (Whenever you cast a noncreature spell, they get +1/+1 until end of turn.)

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Mage-Ring Bully

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Mage-Ring Bully attacks each combat if able.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Shock

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.