Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever Kappa Cannoneer or another artifact you control enters, put a +1/+1 counter on Kappa Cannoneer and it can't be blocked this turn.

Nahiri's Sacrifice

As an additional cost to cast this spell, sacrifice an artifact or creature with mana value X.
Nahiri's Sacrifice deals X damage divided as you choose among any number of target creatures.

Chromescale Drake

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Chromescale Drake enters, reveal the top three cards of your library. Put all artifact cards revealed this way into your hand and the rest into your graveyard.

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.)

Tezzeret, Master of the Bridge

Creature and planeswalker spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)
+2: Tezzeret, Master of the Bridge deals X damage to each opponent, where X is the number of artifacts you control. You gain X life.
−3: Return target artifact card from your graveyard to your hand.
−8: Exile the top ten cards of your library. Put all artifact cards from among them onto the battlefield.

Dreadhorde Arcanist

Trample
Whenever Dreadhorde Arcanist attacks, you may cast target instant or sorcery card with mana value less than or equal to Dreadhorde Arcanist's power from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Cyberdrive Awakener

Flying
Other artifact creatures you control have flying.
When Cyberdrive Awakener enters, until end of turn, each noncreature artifact you control becomes an artifact creature with base power and toughness 4/4.

Eldrazi Monument

Creatures you control get +1/+1 and have flying and indestructible.
At the beginning of your upkeep, sacrifice a creature. If you can't, sacrifice Eldrazi Monument.

Artificer's Dragon

Flying
{R}: Artifact creatures you control get +1/+0 until end of turn.
Unearth {3}{R}{R} ({3}{R}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Draco

Domain — This spell costs {2} less to cast for each basic land type among lands you control.
Flying
Domain — At the beginning of your upkeep, sacrifice Draco unless you pay {10}. This cost is reduced by {2} for each basic land type among lands you control.

Llanowar Wastes

{T}: Add {C}.
{T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Great Furnace

Mistvault Bridge

Mistvault Bridge enters tapped.
Indestructible
{T}: Add {U} or {B}.

Metalworker

{T}: Reveal any number of artifact cards in your hand. Add {C}{C} for each card revealed this way.

Mox Opal

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Goblin Welder

{T}: Choose target artifact a player controls and target artifact card in that player's graveyard. If both targets are still legal as this ability resolves, that player simultaneously sacrifices the artifact and returns the artifact card to the battlefield.

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Vault of Whispers

Kuldotha Forgemaster

{T}, Sacrifice three artifacts: Search your library for an artifact card, put it onto the battlefield, then shuffle.

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Cybermen Squadron

Nonlegendary artifact creatures you control have myriad. (Whenever a creature with myriad attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Armory Automaton

Whenever Armory Automaton enters or attacks, you may attach any number of target Equipment to it. (Control of the Equipment doesn't change.)

Wirewood Lodge

{T}: Add {C}.
{G}, {T}: Untap target Elf.

Gilt-Leaf Palace

As Gilt-Leaf Palace enters, you may reveal an Elf card from your hand. If you don't, Gilt-Leaf Palace enters tapped.
{T}: Add {B} or {G}.

Cryptothrall

Protector — Other artifact creatures you control have hexproof.

Seat of the Synod

Vedalken Certarch

Metalcraft — {T}: Tap target artifact, creature, or land. Activate only if you control three or more artifacts.

Thopter Engineer

When Thopter Engineer enters, create a 1/1 colorless Thopter artifact creature token with flying.
Artifact creatures you control have haste. (They can attack and {T} as soon as they come under your control.)

Stoic Rebuttal

Metalcraft — This spell costs {1} less to cast if you control three or more artifacts.
Counter target spell.

Cyberman Patrol

Artifact creatures you control have afflict 3. (Whenever a creature with afflict 3 becomes blocked, defending player loses 3 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.)

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.)

Razorfield Rhino

Metalcraft — Razorfield Rhino gets +2/+2 as long as you control three or more artifacts.

Karn, Legacy Reforged

Karn, Legacy Reforged's power and toughness are each equal to the greatest mana value among artifacts you control.
At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.

Blightsteel Colossus

Trample, infect, indestructible
If Blightsteel Colossus would be put into a graveyard from anywhere, reveal Blightsteel Colossus and shuffle it into its owner's library instead.

Darksteel Monolith

Indestructible
Once each turn, you may pay {0} rather than pay the mana cost for a colorless spell you cast from your hand.

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return Metalwork Colossus from your graveyard to your hand.