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 Ball Lightning.

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature enters the battlefield under your control, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Arc Lightning

Arc Lightning deals 3 damage divided as you choose among one, two, or three targets.

Viashino Pyromancer

When Viashino Pyromancer enters the battlefield, it deals 2 damage to target player or planeswalker.