The Forgemaster

Menace, Trample, Haste.
The Forgemaster costs {3} less to cast if you control at least 5 or more Artifacts.
When The Forgemaster enters the battlefield, search your library, graveyard, and exile for a card The Aetherium Forge, and put it into your hand. As long as The Forgemaster remains on the battlefield, The Aetherium Forge costs {4} less to cast.
None shall pass, for none are worthy!