Myr Enforcer

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

Frogmite

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Dispel

Galvanic Blast

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

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Prophetic Prism

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

Thoughtcast

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

Gearseeker Serpent

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

Darksteel Citadel

Flayer Husk

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.
Equip {2}

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Chromatic Star

{1}, {T}, Sacrifice Chromatic Star: Add one mana of any color.
When Chromatic Star is put into a graveyard from the battlefield, draw a card.

Great Furnace

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Gorilla Shaman

{X}{X}{1}: Destroy target noncreature artifact with mana value X.

Seat of the Synod

Springleaf Drum

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

Navigator's Compass

When Navigator's Compass enters, you gain 3 life.
{T}: Until end of turn, target land you control becomes the basic land type of your choice in addition to its other types.

Carapace Forger

Metalcraft — Carapace Forger gets +2/+2 as long as you control three or more artifacts.