Steel Overseer

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

Silver Myr

Gleaming Geardrake

Flying
When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice an artifact, put a +1/+1 counter on this creature.

Corridor Monitor

When this creature enters, untap target artifact or creature you control.

Island

Master of Etherium

Master of Etherium's power and toughness are each equal to the number of artifacts you control.
Other artifact creatures you control get +1/+1.

Frogmite

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

Welding Sparks

Welding Sparks deals X damage to target creature, where X is 3 plus the number of artifacts you control.

Jhoira, Ageless Innovator

{T}: Put two ingenuity counters on Jhoira, then you may put an artifact card with mana value X or less from your hand onto the battlefield, where X is the number of ingenuity counters on Jhoira.

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, draw two cards.

Meteor Golem

When this creature enters, destroy target nonland permanent an opponent controls.

Melded Moxite

When this artifact enters, you may discard a card. If you do, draw two cards.
{3}, Sacrifice this artifact: Create a tapped 2/2 colorless Robot artifact creature token.