Fireblast

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

Smash to Smithereens

Destroy target artifact. Smash to Smithereens deals 3 damage to that artifact's controller.

Wrenn's Resolve

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

Mountain

Kessig Flamebreather

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

Curse of the Pierced Heart

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

Flaring Pain

Damage can't be prevented this turn.
Flashback {R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Thermo-Alchemist

Defender
{T}: This creature deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap this creature.

Incinerate

Incinerate deals 3 damage to any target. A creature dealt damage this way can't be regenerated this turn.

Shock

End the Festivities

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

Lava Spike

Lava Spike deals 3 damage to target player or planeswalker.

Voldaren Epicure

When this creature enters, it deals 1 damage to each opponent. Create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Lightning Strike

Lightning Strike deals 3 damage to any target.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Needle Drop

Needle Drop deals 1 damage to any target that was dealt damage this turn.
Draw a card.

Searing Blaze

Searing Blaze deals 1 damage to target player or planeswalker and 1 damage to target creature that player or that planeswalker's controller controls.
Landfall — If you had a land enter the battlefield under your control this turn, Searing Blaze deals 3 damage to that player or planeswalker and 3 damage to that creature instead.

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.)

Forgotten Cave

This land enters tapped.
{T}: Add {R}.
Cycling {R} ({R}, Discard this card: Draw a card.)

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.