Darksteel Citadel

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Auriok Sunchaser

Metalcraft — As long as you control three or more artifacts, Auriok Sunchaser gets +2/+2 and has flying.

Basilica Skullbomb

{1}, Sacrifice Basilica Skullbomb: Draw a card.
{2}{W}, Sacrifice Basilica Skullbomb: Target creature you control gets +2/+2 and gains flying until end of turn. Draw a card. Activate only as a sorcery.

Plains

Court Homunculus

Court Homunculus gets +1/+1 as long as you control another artifact.

Ancient Den

Filigree Familiar

When Filigree Familiar enters, you gain 2 life.
When Filigree Familiar dies, draw a card.

War Report

You gain life equal to the number of creatures on the battlefield plus the number of artifacts on the battlefield.

Apostle's Blessing

({W/P} can be paid with either {W} or 2 life.)
Target artifact or creature you control gains protection from artifacts or from the color of your choice until end of turn.

Ghalma's Warden

Metalcraft — Ghalma's Warden gets +2/+2 as long as you control three or more artifacts.

Crimson Acolyte

Protection from red
{W}: Target creature gains protection from red until end of turn.

Ardent Recruit

Metalcraft — Ardent Recruit gets +2/+2 as long as you control three or more artifacts.

Mandible Justiciar

Lifelink
Whenever another artifact you control enters, Mandible Justiciar gets +1/+1 until end of turn.

Mana Tithe

Counter target spell unless its controller pays {1}.

Blacksmith's Skill

Target permanent gains hexproof and indestructible until end of turn. If it's an artifact creature, it gets +2/+2 until end of turn.

Lembas

When Lembas enters, scry 1, then draw a card.
{2}, {T}, Sacrifice Lembas: You gain 3 life.
When Lembas is put into a graveyard from the battlefield, its owner shuffles it into their library.

Dispeller's Capsule

{2}{W}, {T}, Sacrifice Dispeller's Capsule: Destroy target artifact or enchantment.