Drossforge Bridge

Drossforge Bridge enters tapped.
Indestructible
{T}: Add {B} or {R}.

Myr Enforcer

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

Experimental Synthesizer

When Experimental Synthesizer enters or leaves the battlefield, exile the top card of your library. Until end of turn, you may play that card.
{2}{R}, Sacrifice Experimental Synthesizer: Create a 2/2 white Samurai creature token with vigilance. Activate only as a sorcery.

Frogmite

Thoughtcast

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

Ornithopter

Vault of Whispers

Maelstrom Colossus

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Consuming Sepulcher

At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Tithing Blade

When Tithing Blade enters, each opponent sacrifices a creature of their choice.
Craft with creature {4}{B} ({4}{B}, Exile this artifact, Exile a creature you control or a creature card from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Tithing Blade // Consuming Sepulcher

Darksteel Citadel

Island

Vault Skirge

({B/P} can be paid with either {B} or 2 life.)
Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Mistvault Bridge

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

Gearseeker Serpent

This spell costs {1} less to cast for each artifact you control.
{5}{U}: Gearseeker Serpent can't be blocked this turn.

Silverbluff Bridge

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

Seat of the Synod

Metallic Rebuke

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Counter target spell unless its controller pays {3}.

Galvanic Blast

Galvanic Blast deals 2 damage to any target.
Metalcraft — Galvanic Blast deals 4 damage instead if you control three or more artifacts.

Great Furnace

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mountain

Oaken Siren

Flying, vigilance
{T}: Add {U}. Spend this mana only to cast an artifact spell or activate an ability of an artifact source.