Have

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

Skullcrack

Players can't gain life this turn. Damage can't be prevented this turn. Skullcrack deals 3 damage to target player or planeswalker.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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.

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Shock

Ruby Medallion

Red spells you cast cost {1} less to cast.

Ral, Leyline Prodigy

Ral, Leyline Prodigy enters with an additional loyalty counter on him for each instant and sorcery spell you've cast this turn.
+1: Until your next turn, instant and sorcery spells you cast cost {1} less to cast.
−2: Ral deals 2 damage divided as you choose among one or two targets. Draw a card if you control a blue permanent other than Ral.
−8: Exile the top eight cards of your library. You may cast instant and sorcery spells from among them this turn without paying their mana costs.

Ral, Monsoon Mage

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell during your turn, flip a coin. If you lose the flip, Ral, Monsoon Mage deals 1 damage to you. If you win the flip, you may exile Ral. If you do, return him to the battlefield transformed under his owner's control.

Ral, Monsoon Mage // Ral, Leyline Prodigy

Mountain

Flame Rift

Flame Rift deals 4 damage to each player.

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.