Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Darksteel Relic

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

Battered Golem

Battered Golem doesn't untap during your untap step.
Whenever an artifact enters, you may untap Battered Golem.

Elusive Spellfist

Whenever you cast a noncreature spell, Elusive Spellfist gets +1/+0 until end of turn and can't be blocked this turn.

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Memnite

Thirst for Knowledge

Draw three cards. Then discard two cards unless you discard an artifact card.

Darksteel Citadel

Mizzium Skin

Target creature you control gets +0/+1 and gains hexproof until end of turn.
Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Mirran Spy

Flying
Whenever you cast an artifact spell, you may untap target creature.

Academy Ruins

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

Spell Snare

Banishing Knack

Until end of turn, target creature gains "{T}: Return target nonland permanent to its owner's hand."

Remand

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard.
Draw a card.

Inventors' Fair

At the beginning of your upkeep, if you control three or more artifacts, you gain 1 life.
{T}: Add {C}.
{4}, {T}, Sacrifice Inventors' Fair: Search your library for an artifact card, reveal it, put it into your hand, then shuffle. Activate only if you control three or more artifacts.