This might be simple or more difficult than it’s worth, but I’ve read that the most important distinction between katana and its precursor, the Tachi, is how each were worn. The Tachi was the sword wielded by samurai during the time of GoT, and they even call their swords that in the Japanese dub.
I think it’d be cool if someone could mod it so the swords ronin and samurai wear on their bodies are flipped. Instead of being worn down through the belt, they’re flipped upwards instead.