Myr Enforcer

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

Mountain

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

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

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

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

Metalcraft — Carapace Forger gets +2/+2 as long as you control three or more artifacts.

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

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

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.