Hovermyr

Myr Enforcer

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

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Etched Champion

Metalcraft — Etched Champion has protection from each color as long as you control three or more artifacts.

Arcbound Ravager

Sacrifice an artifact: Put a +1/+1 counter on Arcbound Ravager.
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.)

Juggernaut

Juggernaut attacks each combat if able.
Juggernaut can't be blocked by Walls.

Mishra's Workshop

{T}: Add {C}{C}{C}. Spend this mana only to cast artifact spells.

Whipflare

Whipflare deals 2 damage to each nonartifact creature.

Memnite

Wurmcoil Engine

Deathtouch, lifelink
When Wurmcoil Engine dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.