Have

Firespitter Whelp

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

Mountain

Burning

Flames of the Firebrand

Flames of the Firebrand deals 3 damage divided as you choose among one, two, or three targets.

Hearts on Fire

One or two target creatures each get +2/+1 until end of turn.

Firebrand Archer

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

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Wildfire Elemental

Whenever an opponent is dealt noncombat damage, creatures you control get +1/+0 until end of turn.

Play with Fire

Play with Fire deals 2 damage to any target. If a player is dealt damage this way, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Jaya's Firenado

Jaya's Firenado deals 5 damage to target creature or planeswalker. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Fathom Fleet Firebrand

{1}{R}: This creature gets +1/+0 until end of turn.

Chandra's Spitfire

Flying
Whenever an opponent is dealt noncombat damage, this creature gets +3/+0 until end of turn.

Rionya, Fire Dancer

At the beginning of combat on your turn, create X tokens that are copies of another target creature you control, where X is one plus the number of instant and sorcery spells you've cast this turn. They gain haste. Exile them at the beginning of the next end step.

Goblin Dark-Dwellers

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, you may cast target instant or sorcery card with mana value 3 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Goblin Fireslinger

{T}: This creature deals 1 damage to target player or planeswalker.