Darksteel Citadel

Cranial Plating

Equipped creature gets +1/+0 for each artifact you control.
{B}{B}: Attach Cranial Plating to target creature you control.
Equip {1}

Nettlecyst

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1 for each artifact and/or enchantment you control.
Equip {2}

Frogmite

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

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Thought Monitor

Affinity for artifacts
Flying
When Thought Monitor enters, draw two cards.

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Myr Enforcer

Salvage Titan

You may sacrifice three artifacts rather than pay this spell's mana cost.
Exile three artifact cards from your graveyard: Return Salvage Titan from your graveyard to your hand.

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.)

Emrakul, the Aeons Torn

This spell can't be countered.
When you cast this spell, take an extra turn after this one.
Flying, protection from spells that are one or more colors, annihilator 6
When Emrakul, the Aeons Torn is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

Thoughtcast

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

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Gut Shot

({R/P} can be paid with either {R} or 2 life.)
Gut Shot deals 1 damage to any target.

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Broodstar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
Broodstar's power and toughness are each equal to the number of artifacts you control.

The Antiquities War

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Look at the top five cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
III — Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

Ornithopter

Spire of Industry

{T}: Add {C}.
{T}, Pay 1 life: Add one mana of any color. Activate only if you control an artifact.

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.