Hellkite Tyrant

Flying, trample
Whenever this creature deals combat damage to a player, gain control of all artifacts that player controls.
At the beginning of your upkeep, if you control twenty or more artifacts, you win the game.

Secluded Starforge

{T}: Add {C}.
{2}, {T}, Tap X untapped artifacts you control: Target creature gets +X/+0 until end of turn. Activate only as a sorcery.
{5}, {T}: Create a 2/2 colorless Robot artifact creature token.

Weapons Manufacturing

Whenever a nontoken artifact you control enters, create a colorless artifact token named Munitions with "When this token leaves the battlefield, it deals 2 damage to any target."

Great Furnace

Chiss-Goria, Forge Tyrant

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying, haste
Whenever Chiss-Goria attacks, exile the top five cards of your library. You may cast an artifact spell from among them this turn. If you do, it has affinity for artifacts.

Treasure Nabber

Whenever an opponent taps an artifact for mana, gain control of that artifact until the end of your next turn.

Zookeeper Mechan

{T}: Add {R}.
{6}{R}: Target creature you control gets +4/+0 until end of turn. Activate only as a sorcery.