Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Rally the Peasants

Creatures you control get +2/+0 until end of turn.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Ancient Den

Bitter Reunion

When Bitter Reunion enters, you may discard a card. If you do, draw two cards.
{1}, Sacrifice Bitter Reunion: Creatures you control gain haste until end of turn.

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.

Nimblewright Schematic

When Nimblewright Schematic enters or is put into a graveyard from the battlefield, create a 1/1 colorless Construct artifact creature token.

Implement of Combustion

{R}, Sacrifice Implement of Combustion: It deals 1 damage to target player or planeswalker.
When Implement of Combustion is put into a graveyard from the battlefield, draw a card.

Makeshift Munitions

{1}, Sacrifice an artifact or creature: Makeshift Munitions deals 1 damage to any target.

Great Furnace

Plains

Kuldotha Rebirth

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

Clowning Around

Create two 1/1 white Clown Robot artifact creature tokens, then roll a six-sided die. If the result is equal to or less than the number of Robots you control, create a 1/1 white Clown Robot artifact creature token.

Circuits Act

Roll three six-sided dice. For each different result, create a 1/1 white Clown Robot artifact creature token.

Rustvale Bridge

Rustvale Bridge enters tapped.
Indestructible
{T}: Add {R} or {W}.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Goblin Bushwhacker

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

Mountain

Myr Enforcer

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)