Galvanic Blast

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

Ornithopter

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

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

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Metalcraft — This spell costs {1} less to cast if you control three or more artifacts.
Counter target spell.

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

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

At the beginning of the end step, if you control no artifacts, sacrifice Glimmervoid.
{T}: Add one mana of any color.

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.

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

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.