Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Cinder Pyromancer

{T}: Cinder Pyromancer deals 1 damage to target player or planeswalker.
Whenever you cast a red spell, you may untap Cinder Pyromancer.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Surreal Memoir

Return an instant card at random from your graveyard to your hand.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Magma Jet

Magma Jet deals 2 damage to any target. Scry 2.

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Shrine of Burning Rage

At the beginning of your upkeep and whenever you cast a red spell, put a charge counter on Shrine of Burning Rage.
{3}, {T}, Sacrifice Shrine of Burning Rage: It deals damage equal to the number of charge counters on it to any target.

Pyretic Ritual

Shock

Chain Reaction

Chain Reaction deals X damage to each creature, where X is the number of creatures on the battlefield.

Volt Charge

Volt Charge deals 3 damage to any target. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Grinning Ignus

{R}, Return Grinning Ignus to its owner's hand: Add {C}{C}{R}. Activate only as a sorcery.

Quest for Pure Flame

Whenever a source you control deals damage to an opponent, you may put a quest counter on Quest for Pure Flame.
Remove four quest counters from Quest for Pure Flame and sacrifice it: If any source you control would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

Wild Guess

As an additional cost to cast this spell, discard a card.
Draw two cards.

Staggershock

Staggershock deals 2 damage to any target.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Mountain

Skullcrack

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

Guttersnipe

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

Seething Song

Spark Jolt

Spark Jolt deals 1 damage to any target. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)