Stingscourger

Echo {3}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Stingscourger enters, return target creature an opponent controls to its owner's hand.

Smash to Smithereens

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

End the Festivities

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

Fireblast

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

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Foundry Street Denizen

Whenever another red creature you control enters, Foundry Street Denizen gets +1/+0 until end of turn.

Voldaren Epicure

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

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mountain

Goblin Grenade

As an additional cost to cast this spell, sacrifice a Goblin.
Goblin Grenade deals 5 damage to any target.

Great Furnace

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.)

Experimental Synthesizer

When Experimental Synthesizer enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice Experimental Synthesizer: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.

Mogg War Marshal

Echo {1}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Mogg War Marshal enters or dies, create a 1/1 red Goblin creature token.

Goblin Bushwhacker

Kicker {R} (You may pay an additional {R} as you cast this spell.)
When this creature enters, if it was kicked, creatures you control get +1/+0 and gain haste until end of turn.

Goblin Sledder

Sacrifice a Goblin: Target creature gets +1/+1 until end of turn.

Kuldotha Rebirth

As an additional cost to cast this spell, sacrifice an artifact.
Create three 1/1 red Goblin creature tokens.

Reckless Impulse

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

Shenanigans

Destroy target artifact.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)

Dark-Dweller Oracle

{1}, Sacrifice a creature: Exile the top card of your library. You may play that card this turn. (You still pay its costs. You can play a land this way only if you have an available land play remaining.)