I am not a programmer otherwise I would add this myself, but I would like to see a RP fighting option added with customizable item shops and weapon damages so that my viewers can enjoy the benefits of RP wars with a more structured RP style.
This seems like something that would be better suited for a custom module. And based on your description it sounds like it would be a very lengthy one to write.
You could maybe use the pokemon/waifu game and convert it then add a shop? That’d probably be the “easiest” route.
However, if anyone was to write this, I believe they’d need a lot more detail than just saying that you want RP fighting.