Fire Servant

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

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, Chandra's Spitfire gets +3/+0 until end of turn.

Berserkers of Blood Ridge

Berserkers of Blood Ridge attacks each combat if able.

Prodigal Pyromancer

{T}: Prodigal Pyromancer deals 1 damage to any target.

Ember Hauler

{1}, Sacrifice Ember Hauler: It deals 2 damage to any target.

Canyon Minotaur

Chandra's Outrage

Chandra's Outrage deals 4 damage to target creature and 2 damage to that creature's controller.

Thunder Strike

Target creature gets +2/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Shiv's Embrace

Enchant creature
Enchanted creature gets +2/+2 and has flying.
{R}: Enchanted creature gets +1/+0 until end of turn.

Mountain

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Volcanic Strength

Enchant creature
Enchanted creature gets +2/+2 and has mountainwalk. (It can't be blocked as long as defending player controls a Mountain.)

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.