Myr Enforcer

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

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Ardent Recruit

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

Flayer Husk

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Equip {2}

Arcbound Worker

Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Plains

Bone Saw

Equipped creature gets +1/+0.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Arcbound Stinger

Flying
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Court Homunculus

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

Arcbound Prototype

Modular 2 (This creature enters with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Arcbound Mouser

Lifelink
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Ancient Den

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.

Kirtar's Desire

Enchant creature
Enchanted creature can't attack.
Threshold — Enchanted creature can't block as long as seven or more cards are in your graveyard.

Darksteel Citadel

Auriok Sunchaser

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