Mountain

Ornithopter

Atog

Sacrifice an artifact: This creature gets +2/+2 until end of turn.

Tormod's Crypt

{T}, Sacrifice this artifact: Exile target player's graveyard.

Ravenous Intruder

Blood Moon

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Welding Jar

Sacrifice this artifact: Regenerate target artifact.

Pia's Revolution

Whenever a nontoken artifact is put into your graveyard from the battlefield, return that card to your hand unless target opponent has this enchantment deal 3 damage to them.

Mishra's Bauble

{T}, Sacrifice this artifact: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Memnite

Krark-Clan Shaman

Sacrifice an artifact: This creature deals 1 damage to each creature without flying.