So I've agreed that in my world building.
Obsidian is a kind of moldable magical Play-Doh that people can make weapons and armor out of but I don't know what it should do or why you're able to mold it like Play-Doh.
But I just want my men and women to run around in scantily clad outfits while having cool as fuck black armor that's extremely powerful and I can't think of a lore idea or justification on how to do this.