Imskir Iron-Eater

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When Imskir Iron-Eater enters, you draw X cards and you lose X life, where X is half the number of artifacts you control, rounded down.
{3}{R}, Sacrifice an artifact: Imskir deals damage equal to the sacrificed artifact's mana value to any target.

Darksteel Citadel

Blackcleave Cliffs

Blackcleave Cliffs enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

Spire of Industry

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

Gingerbrute

Haste
{1}: Gingerbrute can't be blocked this turn except by creatures with haste.
{2}, {T}, Sacrifice Gingerbrute: You gain 3 life.

Etherium Pteramander

Flying
Etherium Pteramander can block only creatures with flying.
{6}{B}: Adapt 4. This ability costs {1} less to activate for each other artifact you control. (If this creature has no +1/+1 counters on it, put four +1/+1 counters on it.)

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Cranial Plating

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

Swamp

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Cranial Ram

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+1, where X is the number of artifacts you control.
Equip {2}

Ornithopter

Drossforge Bridge

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

Memnite

Galvanic Blast

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

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.)

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.)