Tower Worker

Reach
{T}: Add {C}. If you control creatures named Mine Worker and Power Plant Worker, add {C}{C}{C} instead.

Great Furnace

Mine Worker

{T}: You gain 1 life. If you control creatures named Power Plant Worker and Tower Worker, you gain 3 life instead.

Urza's Command

Choose two —
• Creatures you don't control get -2/-0 until end of turn.
• Create a tapped Powerstone token.
• Create a tapped 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."
• Scry 1, then draw a card.

Powerstone Shard

{T}: Add {C} for each artifact you control named Powerstone Shard.

Power Plant Worker

{3}: Power Plant Worker gets +2/+2 until end of turn. If you control creatures named Mine Worker and Tower Worker, put two +1/+1 counters on Power Plant Worker instead. Activate only once each turn.

Hexavus

Flying
Hexavus enters with six +1/+1 counters on it.
{1}, Remove a +1/+1 counter from Hexavus: Put a flying counter on another target creature.
{1}, Remove a counter from another creature you control: Put a +1/+1 counter on Hexavus.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Foundry Inspector

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

Etched Champion

Metalcraft — Etched Champion has protection from each color as long as you control three or more artifacts.

Silverbluff Bridge

Silverbluff Bridge enters tapped.
Indestructible
{T}: Add {U} or {R}.

Sol Ring

Visions of Phyrexia

At the beginning of your upkeep, exile the top card of your library. You may play that card this turn.
At the beginning of your end step, if you didn't play a card from exile this turn, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Darksteel Juggernaut

Indestructible
Darksteel Juggernaut's power and toughness are each equal to the number of artifacts you control.
Darksteel Juggernaut attacks each combat if able.

Arcane Encyclopedia

Hall of Tagsin

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
{4}, {T}: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

The Brothers' War

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create two tapped Powerstone tokens.
II — Choose two target players. Until your next turn, each creature they control attacks the other chosen player each combat if able.
III — The Brothers' War deals X damage to any target and X damage to any other target, where X is the number of artifacts you control.

Darksteel Citadel

Seat of the Synod

Bonder's Ornament

{T}: Add one mana of any color.
{4}, {T}: Each player who controls a permanent named Bonder's Ornament draws a card.

Stern Lesson

Draw two cards, then discard a card. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")

Thran Dynamo

Prophetic Prism

When Prophetic Prism enters, draw a card.
{1}, {T}: Add one mana of any color.

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Horned Stoneseeker

Menace
When Horned Stoneseeker enters, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")
When Horned Stoneseeker leaves the battlefield, sacrifice a Powerstone.

Karn, Living Legacy

+1: Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")
−1: Pay any amount of mana. Look at that many cards from the top of your library, then put one of those cards into your hand and the rest on the bottom of your library in a random order.
−7: You get an emblem with "Tap an untapped artifact you control: This emblem deals 1 damage to any target."