Lodestone Myr

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

Brass Gnat

Flying
This creature doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {1}. If you do, untap this creature.

Adaptive Gemguard

Tap two untapped artifacts and/or creatures you control: Put a +1/+1 counter on this creature. Activate only as a sorcery.

Brass Man

This creature doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {1}. If you do, untap this creature.

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Ghirapur Aether Grid

Tap two untapped artifacts you control: This enchantment deals 1 damage to any target.

Network Terminal

{T}: Add one mana of any color.
{1}, {T}, Tap another untapped artifact you control: Draw a card, then discard a card.

Juntu Stakes

Creatures with power 1 or less don't untap during their controllers' untap steps.

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Battered Golem

This creature doesn't untap during your untap step.
Whenever an artifact enters, you may untap this creature.

Bladewheel Chariot

Tap two other untapped artifacts you control: This Vehicle becomes an artifact creature until end of turn.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Spring-Loaded Sawblades

Flash
When this artifact enters, it deals 5 damage to target tapped creature an opponent controls.
Craft with artifact {3}{W} ({3}{W}, Exile this artifact, Exile another artifact you control or an artifact card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)