Yeah, I was trying to have it represent iron.
The idea with Act 2 is that Valhalla will be fairly empty to start the Act - one of Brunhilde's abilities is to bring a nearly humanoid foe to Valhalla to take their place among the Gods. I have it set up similar to Pokémon's monster capture system. Among other things, as you "capture" more and more people and bring them into Valhalla, there will be more people in it when you go to visit (it's accessible via the worldmap). The smithy is particularly important for upgrading her Valkyrie equipment; a spear, armor, and a helm. The spear is important because it's not only an equippable item, but can be used via the skill menu if you have another item equipped. This allows you to put together some strategy as I've emphasized weapon weaknesses in battles.