Guidelight Synergist

Flying
This creature gets +1/+0 for each artifact you control.

Monoist Circuit-Feeder

Flying
When this creature enters, until end of turn, target creature you control gets +X/+0 and target creature an opponent controls gets -0/-X, where X is the number of artifacts you control.

Memory Guardian

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying

Valkyrie Aerial Unit

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Emissary Escort

This creature gets +X/+0, where X is the greatest mana value among other artifacts you control.

Mechan Assembler

Whenever another artifact you control enters, create a 2/2 colorless Robot artifact creature token. This ability triggers only once each turn.

Monoist Sentry

Hullcarver

Starport Security

{3}{W}, {T}: Tap another target creature. This ability costs {2} less to activate if you control a creature with a +1/+1 counter on it.

Retrieve the Esper

Create a 3/3 blue Robot Warrior artifact creature token. Then if this spell was cast from a graveyard, put two +1/+1 counters on that token.
Flashback {5}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Nesting Bot

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
When this creature dies, create a 1/1 colorless Servo artifact creature token.
Max speed — This creature gets +1/+0.

Cogwork Wrestler

Flash
When this creature enters, target creature an opponent controls gets -2/-0 until end of turn.

Research Thief

Flash
Flying
Whenever an artifact creature you control deals combat damage to a player, draw a card.

Dauntless Scrapbot

When this creature enters, exile each opponent's graveyard. Create a Lander token. (It's an artifact with "{2}, {T}, Sacrifice this token: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.")

Urza, Chief Artificer

Affinity for artifact creatures (This spell costs {1} less to cast for each artifact creature you control.)
Artifact creatures you control have menace.
At the beginning of your end step, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Mechan Shieldmate

Defender
As long as an artifact entered the battlefield under your control this turn, this creature can attack as though it didn't have defender.

Uthros Research Craft

Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 12+.)
3+ | Whenever you cast an artifact spell, draw a card. Put a charge counter on this Spacecraft.
12+ | Flying
This Spacecraft gets +1/+0 for each artifact you control.

Scorpion Sentinel

As long as you control seven or more lands, this creature gets +3/+0.

Traxos, Scourge of Kroog

Trample
Traxos enters tapped and doesn't untap during your untap step.
Whenever you cast a historic spell, untap Traxos. (Artifacts, legendaries, and Sagas are historic.)

Magitek Infantry

This creature gets +1/+0 as long as you control another artifact.
{2}{W}: Search your library for a card named Magitek Infantry, put it onto the battlefield tapped, then shuffle.