Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Steel Overseer

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

Etched Champion

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

Iron Myr

Island

Bomat Courier

Haste
Whenever this creature attacks, exile the top card of your library face down. (You can't look at it.)
{R}, Discard your hand, Sacrifice this creature: Put all cards exiled with this creature into their owners' hands.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return this card from your graveyard to your hand.

Mountain

Steel Hellkite

Flying
{2}: This creature gets +1/+0 until end of turn.
{X}: Destroy each nonland permanent with mana value X whose controller was dealt combat damage by this creature this turn. Activate only once each turn.

Sol Ring

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Jhoira's Familiar

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

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice this land: You may cast spells this turn as though they had flash.