Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Archaeomender

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

Workshop Assistant

When Workshop Assistant dies, return another target artifact card from your graveyard to your hand.

Trickster Mage

{U}, {T}, Discard a card: You may tap or untap target artifact, creature, or land.

Forge of Heroes

{T}: Add {C}.
{T}: Choose target commander that entered this turn. Put a +1/+1 counter on it if it's a creature and a loyalty counter on it if it's a planeswalker.

Urza, Powerstone Prodigy

Vigilance
{1}, {T}: Draw a card, then discard a card.
Whenever you discard one or more artifact cards, create a tapped Powerstone token. This ability triggers only once each turn. (The token is an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Darksteel Citadel

Corridor Monitor

When Corridor Monitor enters, untap target artifact or creature you control.

Opal Palace

{T}: Add {C}.
{1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Etherium Sculptor

Artifact spells you cast cost {1} less to cast.

Etherium Spinner

Whenever you cast a spell with mana value 4 or greater, create a 1/1 colorless Thopter artifact creature token with flying.

Thoughtcast

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

Island

The Surgical Bay

The Surgical Bay enters tapped.
{T}: Add {U}.
{1}{U}, {T}, Sacrifice The Surgical Bay: Draw a card.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Dross Scorpion

Whenever Dross Scorpion or another artifact creature dies, you may untap target artifact.

Saprazzan Skerry

Saprazzan Skerry enters tapped with two depletion counters on it.
{T}, Remove a depletion counter from Saprazzan Skerry: Add {U}{U}. If there are no depletion counters on Saprazzan Skerry, sacrifice it.

Study Hall

{T}: Add {C}.
{1}, {T}: Add one mana of any color. When you spend this mana to cast your commander, scry X, where X is the number of times it's been cast from the command zone this game.

Seat of the Synod

Haunted Fengraf

{T}: Add {C}.
{3}, {T}, Sacrifice Haunted Fengraf: Return a creature card at random from your graveyard to your hand.

Foundry Inspector

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Tocasia's Dig Site

{T}: Add {C}.
{3}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)