Aether Swooper

Flying
When Aether Swooper enters, you get {E}{E} (two energy counters).
Whenever Aether Swooper attacks, you may pay {E}{E}. If you do, create a 1/1 colorless Servo artifact creature token.

Tree of Tales

Forest

Seat of the Synod

Great Furnace

Reckless Fireweaver

Whenever an artifact you control enters, Reckless Fireweaver deals 1 damage to each opponent.

Inventor's Goggles

Equipped creature gets +1/+2.
Whenever an Artificer you control enters, you may attach Inventor's Goggles to it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Mirran Mettle

Target creature gets +2/+2 until end of turn.
Metalcraft — That creature gets +4/+4 until end of turn instead if you control three or more artifacts.

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Counterspell

Cliffhaven Kitesail

When Cliffhaven Kitesail enters, attach it to target creature you control.
Equipped creature has flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Gearsmith Prodigy

Gearsmith Prodigy gets +1/+0 as long as you control an artifact.

Carapace Forger

Metalcraft — Carapace Forger gets +2/+2 as long as you control three or more artifacts.

Machinate

Look at the top X cards of your library, where X is the number of artifacts you control. Put one of those cards into your hand and the rest on the bottom of your library in any order.

Galvanic Blast

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