Myr Enforcer

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

Frogmite

Welding Jar

Sacrifice Welding Jar: Regenerate target artifact.

Sojourner's Companion

Affinity for artifacts
Artifact landcycling {2} ({2}, Discard this card: Search your library for an artifact land card, reveal it, put it into your hand, then shuffle.)

Vault of Whispers

Tooth of Chiss-Goria

Flash
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
{T}: Target creature gets +1/+0 until end of turn.

Phyrexian Walker

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

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.)

Memnite

Great Furnace

Ornithopter

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.