I’dk I read the mangas but I can’t really help you because I have only read Kanto-end-of-hoenn

You don't have to read the mangas for inspiration, all i need is some ideas or backstories for my characters so my fanfics aren't like the games

I would say I’m an expert at following the story while making it unique, Try making special character dynamics, family, relations, etc… or even maybe region of origin could change to go far out there.