Great Furnace

Foundry Inspector

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

Shao Jun

Leap Strike — During your turn, Shao Jun has flying and first strike.
Rope Dart — Tap two untapped artifacts you control: Shao Jun deals 1 damage to each opponent.

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever Kappa Cannoneer or another artifact you control enters, put a +1/+1 counter on Kappa Cannoneer and it can't be blocked this turn.

Etherium Sculptor

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Seat of the Synod

Darksteel Citadel

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)