Darksteel Citadel

Gearseeker Serpent

This spell costs {1} less to cast for each artifact you control.
{5}{U}: Gearseeker Serpent can't be blocked this turn.

Foundry Inspector

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

Great Furnace

Myr Enforcer

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

Renegade Freighter

Whenever Renegade Freighter attacks, it gets +1/+1 and gains trample until end of turn.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Aradara Express

Menace
Crew 4 (Tap any number of creatures you control with total power 4 or more: This Vehicle becomes an artifact creature until end of turn.)

Etherium Sculptor

Dispel

Funeral Longboat

Vigilance
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Gearsmith Prodigy

Gearsmith Prodigy gets +1/+0 as long as you control an artifact.

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Prophetic Prism

When Prophetic Prism enters, draw a card.
{1}, {T}: Add one mana of any color.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Mobile Garrison

Whenever Mobile Garrison attacks, untap another target artifact or creature you control.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Seat of the Synod

Island

Thoughtcast

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