Have

Lava Dart

Lava Dart deals 1 damage to any target.
Flashback—Sacrifice a Mountain. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Mountain

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.)

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Skewer the Critics

Spectacle {R} (You may cast this spell for its spectacle cost rather than its mana cost if an opponent lost life this turn.)
Skewer the Critics deals 3 damage to any target.

Blazing Crescendo

Target creature gets +3/+1 until end of turn.
Exile the top card of your library. Until the end of your next turn, you may play that card.

Kiln Fiend

Whenever you cast an instant or sorcery spell, Kiln Fiend gets +3/+0 until end of turn.

Dwarven Forge-Chanter

Ward—Pay 2 life. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.)
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Gorilla Shaman

{X}{X}{1}: Destroy target noncreature artifact with mana value X.

Curse of the Pierced Heart

Enchant player
At the beginning of enchanted player's upkeep, Curse of the Pierced Heart deals 1 damage to that player or a planeswalker that player controls.

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

Sawblade Scamp

Haste
Whenever you cast a noncreature spell, put an oil counter on Sawblade Scamp.
{T}, Remove an oil counter from Sawblade Scamp: It deals 1 damage to each opponent.

Shock

Getting

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Wrenn's Resolve

Fireblast

You may sacrifice two Mountains rather than pay this spell's mana cost.
Fireblast deals 4 damage to any target.