Red Sun's Zenith

Red Sun's Zenith deals X damage to any target. If a creature dealt damage this way would die this turn, exile it instead. Shuffle Red Sun's Zenith into its owner's library.

Arc Trail

Arc Trail deals 2 damage to any target and 1 damage to another target.

Hovermyr

Lightning Strike

Lightning Strike deals 3 damage to any target.

Ghitu Lavarunner

As long as there are two or more instant and/or sorcery cards in your graveyard, this creature gets +1/+0 and has haste. (It can attack and {T} as soon as it comes under your control.)

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

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.

Peace Strider

When Peace Strider enters, you gain 3 life.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Pierce Strider

When Pierce Strider enters, target opponent loses 3 life.

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.

Mountain

Perilous Myr

When Perilous Myr dies, it deals 2 damage to any target.

Fire Servant

If a red instant or sorcery spell you control would deal damage, it deals double that damage instead.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)