Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return Metalwork Colossus from your graveyard to your hand.

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Seat of the Synod

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Wastes

Cranial Plating

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

Merchant's Dockhand

{3}{U}, {T}, Tap X untapped artifacts you control: Look at the top X cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Glint Hawk Idol

Whenever another artifact you control enters, you may have Glint Hawk Idol become a 2/2 Bird artifact creature with flying until end of turn.
{W}: Glint Hawk Idol becomes a 2/2 Bird artifact creature with flying until end of turn.

Ancient Den

Darksteel Citadel

Power Depot

Power Depot enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast artifact spells or activate abilities of artifacts.
Modular 1

Weldfast Monitor

{R}: Weldfast Monitor gains menace until end of turn.

Myr Enforcer

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

Vault of Whispers

Tree of Tales

Narnam Cobra

{G}: Narnam Cobra gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Frogmite

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Shimmerdrift Vale

Shimmerdrift Vale enters tapped.
As Shimmerdrift Vale enters, choose a color.
{T}: Add one mana of the chosen color.