Firebolt

Firebolt deals 2 damage to any target.
Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Precision Bolt

Precision Bolt deals 3 damage to any target.

Bolt of Keranos

Bolt of Keranos deals 3 damage to any target. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Neheb, the Eternal

Afflict 3 (Whenever this creature becomes blocked, defending player loses 3 life.)
At the beginning of each of your postcombat main phases, add {R} for each 1 life your opponents have lost this turn.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

Rift Bolt

Rift Bolt deals 3 damage to any target.
Suspend 1—{R} (Rather than cast this card from your hand, you may pay {R} and exile it with a time counter on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Forked Bolt

Forked Bolt deals 2 damage divided as you choose among one or two targets.

Flame Rift

Flame Rift deals 4 damage to each player.

Runaway Steam-Kin

Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin.
Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}.

Mountain

Twin Bolt

Twin Bolt deals 2 damage divided as you choose among one or two targets.

Seething Song

Concussive Bolt

Concussive Bolt deals 4 damage to target player or planeswalker.
Metalcraft — If you control three or more artifacts, creatures controlled by that player or by that planeswalker's controller can't block this turn.

Storm-Kiln Artist

Storm-Kiln Artist gets +1/+0 for each artifact you control.
Magecraft — Whenever you cast or copy an instant or sorcery spell, create a Treasure token.

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.

Thunderbolt

Choose one —
• Thunderbolt deals 3 damage to target player or planeswalker.
• Thunderbolt deals 4 damage to target creature with flying.

Pyretic Ritual

Syr Carah, the Bold

Whenever Syr Carah, the Bold or an instant or sorcery spell you control deals damage to a player, exile the top card of your library. You may play that card this turn.
{T}: Syr Carah deals 1 damage to any target.