Dance with Devils

Create two 1/1 red Devil creature tokens. They have "When this token dies, it deals 1 damage to any target."

Bottle-Cap Blast

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Bottle-Cap Blast deals 5 damage to any target. If excess damage was dealt to a permanent this way, create that many tapped Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Explosive Welcome

Explosive Welcome deals 5 damage to any target and 3 damage to any other target. Add {R}{R}{R}.

Eelectrocute

Eelectrocute deals 2 damage to any target.
You may cast this card from your graveyard as long as you've rolled a 6 this turn. If you cast it this way and it would be put into your graveyard, exile it instead.

Magar of the Magic Strings

{1}{B}{R}: Note the name of target instant or sorcery card in your graveyard and put it onto the battlefield face down. It's a 3/3 creature with "Whenever this creature deals combat damage to a player, you may create a copy of the card with the noted name. You may cast the copy without paying its mana cost" and "If this creature would leave the battlefield, exile it instead of putting it anywhere else."

Brimstone Volley

Brimstone Volley deals 3 damage to any target.
Morbid — Brimstone Volley deals 5 damage instead if a creature died this turn.

Fateful End

Fateful End deals 3 damage to any target. Scry 1.

Annihilating Fire

Annihilating Fire deals 3 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.