Thoughtcast

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

Dispatch

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

Ornithopter

Island

Springleaf Drum

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

Frogmite

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

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Mana Leak

Counter target spell unless its controller pays {3}.

Cranial Plating

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

Etched Champion

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

Ornithopter of Paradise

Myr Enforcer

Memnite

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Thought Monitor enters, draw two cards.

Blacksmith's Skill

Target permanent gains hexproof and indestructible until end of turn. If it's an artifact creature, it gets +2/+2 until end of turn.

Blinkmoth Nexus

{T}: Add {C}.
{1}: Blinkmoth Nexus becomes a 1/1 Blinkmoth artifact creature with flying until end of turn. It's still a land.
{1}, {T}: Target Blinkmoth creature gets +1/+1 until end of turn.