Treasure Nabber

Whenever an opponent taps an artifact for mana, gain control of that artifact until the end of your next turn.

Metallic Mastery

Gain control of target artifact until end of turn. Untap that artifact. It gains haste until end of turn.

Momo's Heist

Gain control of target artifact. Untap it. It gains haste. At the beginning of the next end step, sacrifice it.

Bjorna, Nightfall Alchemist

{T}, Sacrifice an artifact: Bjorna, Nightfall Alchemist deals 1 damage to target creature. Goad that creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Friends forever (You can have two commanders if both have friends forever.)

Elmar, Ulvenwald Informant

Haste
Whenever you cast your second spell each turn, untap target creature, then investigate. (Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card.")
Friends forever (You can have two commanders if both have friends forever.)