Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color to your mana pool.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Inkmoth Nexus

{T}: Add {1} to your mana pool. {1}: Inkmoth Nexus becomes a 1/1 Blinkmoth artifact creature with flying and infect until end of turn. It's still a land. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Arcbound Ravager

Sacrifice an artifact: Put a +1/+1 counter on Arcbound Ravager. Modular 1 (This enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Blinkmoth Nexus

{T}: Add {1} to your mana pool. {1}: Blinkmoth Nexus becomes a 1/1 Blinkmoth artifact creature with flying until end of turn. It's still a land. {1}, {T}: Target Blinkmoth creature gets +1/+1 until end of turn.

Darksteel Citadel

Indestructible (Effects that say "destroy" don't destroy this land.) {T}: Add {1} to your mana pool.

Whipflare

Whipflare deals 2 damage to each nonartifact creature.

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control. {B}{B}: Attach Cranial Plating to target creature you control. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Signal Pest

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.) Signal Pest can't be blocked except by creatures with flying or reach.

Vault Skirge

({B/P} can be paid with either {B} or 2 life.) Flying Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Etched Champion

Metalcraft — Etched Champion has protection from all colors as long as you control three or more artifacts.

Galvanic Blast

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

Memnite

Mox Opal

Metalcraft — {T}: Add one mana of any color to your mana pool. Activate this ability only if you control three or more artifacts.

Master of Etherium

Master of Etherium's power and toughness are each equal to the number of artifacts you control. Other artifact creatures you control get +1/+1.

Ornithopter

Spire of Industry

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Mountain

({T}: Add {R}.)