Osgir, the Reconstructor

Vigilance
{1}, Sacrifice an artifact: Target creature you control gets +2/+0 until end of turn.
{X}, {T}, Exile an artifact card with mana value X from your graveyard: Create two tokens that are copies of the exiled card. Activate only as a sorcery.

Bronze Guardian

Double strike
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Other artifacts you control have ward {2}.
Bronze Guardian's power is equal to the number of artifacts you control.

Myr Retriever

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

Loyal Apprentice

Haste
Lieutenant — At the beginning of combat on your turn, if you control your commander, create a 1/1 colorless Thopter artifact creature token with flying. That token gains haste until end of turn.

Rebbec, Architect of Ascension

Artifacts you control have protection from each mana value among artifacts you control.
Partner (You can have two commanders if both have partner.)

Lodestone Myr

Trample
Tap an untapped artifact you control: Lodestone Myr gets +1/+1 until end of turn.

Organic Extinction

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Destroy all nonartifact creatures.

Marble Diamond

Marble Diamond enters the battlefield tapped.
{T}: Add {W}.

Scrap Trawler

Whenever Scrap Trawler or another artifact you control is put into a graveyard from the battlefield, return to your hand target artifact card in your graveyard with lesser mana value.

Myrsmith

Whenever you cast an artifact spell, you may pay {1}. If you do, create a 1/1 colorless Myr artifact creature token.

Hellkite Tyrant

Flying, trample
Whenever Hellkite Tyrant deals combat damage to a player, gain control of all artifacts that player controls.
At the beginning of your upkeep, if you control twenty or more artifacts, you win the game.

Steel Overseer

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

Wake the Past

Return all artifact cards from your graveyard to the battlefield. They gain haste until end of turn.

Losheel, Clockwork Scholar

Prevent all combat damage that would be dealt to attacking artifact creatures you control.
Whenever one or more artifact creatures enter the battlefield under your control, draw a card. This ability triggers only once each turn.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Ornithopter of Paradise

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Myr Battlesphere

When Myr Battlesphere enters the battlefield, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Alibou, Ancient Witness

Other artifact creatures you control have haste.
Whenever one or more artifact creatures you control attack, Alibou, Ancient Witness deals X damage to any target and you scry X, where X is the number of tapped artifacts you control.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Daretti, Scrap Savant

+2: Discard up to two cards, then draw that many cards.
−2: Sacrifice an artifact. If you do, return target artifact card from your graveyard to the battlefield.
−10: You get an emblem with "Whenever an artifact is put into your graveyard from the battlefield, return that card to the battlefield at the beginning of the next end step."
Daretti, Scrap Savant can be your commander.

Iron Myr

Digsite Engineer

Whenever you cast an artifact spell, you may pay {2}. If you do, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Foundry Inspector

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

Fire Diamond

Fire Diamond enters the battlefield tapped.
{T}: Add {R}.

Palladium Myr

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.