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."

Goblin Bombardment

Sacrifice a creature: Goblin Bombardment deals 1 damage to any target.

Radiating Lightning

Radiating Lightning deals 3 damage to target player and 1 damage to each creature that player controls.

Pyroclasm

Pyroclasm deals 2 damage to each creature.

Goblin Assault

At the beginning of your upkeep, create a 1/1 red Goblin creature token with haste.
Goblin creatures attack each combat if able.

Spikefield Cave

Spikefield Cave enters tapped.
{T}: Add {R}.

Spikefield Hazard

Spikefield Hazard deals 1 damage to any target. If a permanent dealt damage this way would die this turn, exile it instead.

Spikefield Hazard // Spikefield Cave

Smokestack

At the beginning of your upkeep, you may put a soot counter on Smokestack.
At the beginning of each player's upkeep, that player sacrifices a permanent of their choice for each soot counter on Smokestack.

Shake the Foundations

Shake the Foundations deals 1 damage to each creature without flying.
Draw a card.

Krenko's Command

Create two 1/1 red Goblin creature tokens.

Rain of Embers

Rain of Embers deals 1 damage to each creature and each player.

Last Laugh

Whenever a permanent other than Last Laugh is put into a graveyard from the battlefield, Last Laugh deals 1 damage to each creature and each player.
When no creatures are on the battlefield, sacrifice Last Laugh.

End the Festivities

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

Mountain

Goblin Airbrusher

Whenever you place a sticker, create a Treasure token. If it's an art sticker, instead create two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Judith, Carnage Connoisseur

Whenever you cast an instant or sorcery spell, choose one —
• That spell gains deathtouch and lifelink.
• Create a 2/2 red Imp creature token with "When this creature dies, it deals 2 damage to each opponent."

Destructive Force

Each player sacrifices five lands of their choice. Destructive Force deals 5 damage to each creature.

Goblin Gang Leader

When Goblin Gang Leader enters, create two 1/1 red Goblin creature tokens.

Embereth Blaze

Embereth Blaze deals 2 damage to any target. (Then exile this card. You may cast the enchantment later from exile.)

Virtue of Courage

Whenever a source you control deals noncombat damage to an opponent, you may exile that many cards from the top of your library. You may play those cards this turn.

Virtue of Courage // Embereth Blaze

Goblin Chirurgeon

Sacrifice a Goblin: Regenerate target creature.

Electrodominance

Electrodominance deals X damage to any target. You may cast a spell with mana value X or less from your hand without paying its mana cost.

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Swamp

Krenko, Mob Boss

{T}: Create X 1/1 red Goblin creature tokens, where X is the number of Goblins you control.

Goblin Soothsayer

{R}, {T}, Sacrifice a Goblin: Red creatures get +1/+1 until end of turn.

Magma Vein

{R}, Sacrifice a land: Magma Vein deals 1 damage to each creature without flying.