Darksteel Relic

Indestructible (Effects that say "destroy" don't destroy this artifact.)

Pacification Array

{2}, {T}: Tap target artifact or creature.

Argivian Restoration

Return target artifact card from your graveyard to the battlefield.

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Phyrexia's Core

{T}: Add {C}.
{1}, {T}, Sacrifice an artifact: You gain 1 life.

Stoic Rebuttal

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

Urza's Factory

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Assembly-Worker artifact creature token.

Scrapyard Recombiner

Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
{T}, Sacrifice an artifact: Search your library for a Construct card, reveal it, put it into your hand, then shuffle.

Archaeomender

When Archaeomender enters, return target artifact card from your graveyard to your hand.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Memnite

Salvaging Station

{T}: Return target noncreature artifact card with mana value 1 or less from your graveyard to the battlefield.
Whenever a creature dies, you may untap Salvaging Station.

Darksteel Citadel

Tezzeret's Gatebreaker

When Tezzeret's Gatebreaker enters, look at the top five cards of your library. You may reveal a blue or artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
{5}{U}, {T}, Sacrifice Tezzeret's Gatebreaker: Creatures you control can't be blocked this turn.

Scrapheap

Whenever an artifact or enchantment is put into your graveyard from the battlefield, you gain 1 life.

Steel Overseer

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

Seat of the Synod

Efficient Construction

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.

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.

The Antiquities War

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Look at the top five cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
III — Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

Island

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Assert Authority

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.