Arcane Signet

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

Obsidian Obelisk

Obsidian Obelisk enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a multicolored spell.

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Chiss-Goria, Forge Tyrant

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying, haste
Whenever Chiss-Goria, Forge Tyrant 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.

Mountain

Coldsteel Heart

Coldsteel Heart enters tapped.
As Coldsteel Heart enters, choose a color.
{T}: Add one mana of the chosen color.

Guardian Idol

Guardian Idol enters tapped.
{T}: Add {C}.
{2}: Guardian Idol becomes a 2/2 Golem artifact creature until end of turn.

Ebony Fly

Ebony Fly enters tapped.
{T}: Add {C}.
{4}: Roll a d6. Until end of turn, you may have Ebony Fly become an X/X Insect artifact creature with flying, where X is the result.
Whenever Ebony Fly attacks, another target attacking creature gains flying until end of turn.

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Palladium Myr

Frogmyr Enforcer

Prototype {3}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Myr Enforcer

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

Darksteel Citadel

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Iron Myr

Power Depot

Power Depot enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast artifact spells or activate abilities of artifacts.
Modular 1

Frogmite

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Manakin

Planar Atlas

Planar Atlas enters tapped.
When Planar Atlas enters, you may look at the top four cards of your library. If you do, reveal up to one land card from among them, then put that card on top of your library and the rest on the bottom in a random order.
{T}: Add {C}.

Great Furnace

Furnace Hellkite

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
{R}: Furnace Hellkite gets +1/+0 until end of turn.

Scene of the Crime

Scene of the Crime enters tapped.
{T}: Add {C}.
{T}, Tap an untapped creature you control: Add one mana of any color.
{2}, Sacrifice Scene of the Crime: Draw a card.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Treasure Vault

{T}: Add {C}.
{X}{X}, {T}, Sacrifice Treasure Vault: Create X Treasure tokens.

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.)

Thran Dynamo

Apex Observatory

Apex Observatory enters tapped. As it enters, choose a card type shared among two exiled cards used to craft it.
{T}: The next spell you cast this turn of the chosen type can be cast without paying its mana cost.

Eye of Ojer Taq

{T}: Add one mana of any color.
Craft with two that share a card type {6} ({6}, Exile this artifact, Exile the two from among other permanents you control and/or cards from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)