Douans look into vanadium for potential use (vanadium is an IRL element BTW). Vanadium is absolutely not the hardest metal known--titanium wins, though we're not at that stage yet--but using (insert flammable material that I legally can't say here) can melt vanadium into a more usable state. Douans, the ones who figured this out, experimented with vanadium, imbuing it into their arsenal and increasing their durability whilst making armor gleam vermilion. This information has only gotten as far as neighboring countries. Dou is not willing to trade vanadium. Notes and Credits: Up In My Jam (All of a Sudden) ~ Kubbi
