Plains

Slag Strider

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{1}, Sacrifice an artifact: This creature deals 1 damage to any target.

Chiss-Goria, Forge Tyrant

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying, haste
Whenever Chiss-Goria attacks, exile the top five cards of your library. You may cast an artifact spell from among them this turn. If you do, it has affinity for artifacts.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Alibou, Ancient Witness

Other artifact creatures you control have haste.
Whenever one or more artifact creatures you control attack, Alibou deals X damage to any target and you scry X, where X is the number of tapped artifacts you control.

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.

Marble Diamond

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

Scale of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +0/+1 until end of turn.

Lodestone Golem

Nonartifact spells cost {1} more to cast.

Darksteel Citadel

Sol Ring

Darksteel Forge

Artifacts you control have indestructible. (Effects that say "destroy" don't destroy them. Artifact creatures with indestructible can't be destroyed by damage.)

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Myr Enforcer

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

Mox Opal

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

Tooth of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +1/+0 until end of turn.

Rustvale Bridge

This land enters tapped.
Indestructible
{T}: Add {R} or {W}.

Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Lens Flare

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Lens Flare deals 5 damage to target attacking or blocking creature.

Ancient Den

Digsite Engineer

Whenever you cast an artifact spell, you may pay {2}. If you do, create a 0/0 colorless Construct artifact creature token with "This token gets +1/+1 for each artifact you control."

Command Tower

Bosh, Iron Golem

Trample
{3}{R}, Sacrifice an artifact: Bosh deals damage equal to the sacrificed artifact's mana value to any target.

Fire Diamond

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

Skrelv, Defector Mite

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Skrelv can't block.
{W/P}, {T}: Choose a color. Another target creature you control gains toxic 1 and hexproof from that color until end of turn. It can't be blocked by creatures of that color this turn. ({W/P} can be paid with either {W} or 2 life.)

Mycosynth Golem

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Artifact creature spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)

Plated Onslaught

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Creatures you control get +2/+1 until end of turn.

Gold Myr

Frogmite

Skrelv's Hive

At the beginning of your upkeep, you lose 1 life and create a 1/1 colorless Phyrexian Mite artifact creature token with toxic 1 and "This token can't block."
Corrupted — As long as an opponent has three or more poison counters, creatures you control with toxic have lifelink.