Ancient Den

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.

Galvanic Blast

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

Plains

Rustvale Bridge

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

Glint Hawk

Flying
When Glint Hawk enters the battlefield, sacrifice it unless you return an artifact you control to its owner's hand.

Mountain

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.

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.

Ardent Recruit

Metalcraft — Ardent Recruit gets +2/+2 as long as you control three or more artifacts.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Thraben Inspector

When Thraben Inspector enters the battlefield, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Makeshift Munitions

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

Auriok Sunchaser

Metalcraft — As long as you control three or more artifacts, Auriok Sunchaser gets +2/+2 and has flying.

Kuldotha Rebirth

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