Just for the sake of throwing my idea out there. I'm going to write a new character for this game to make sure that it fits the world and tone we're going for. I'm aiming for a genin, so hopefully we'll get a few more of those and/or a jounin to take care of us/me. 

My basic character concept is an ancestor/hero worshipper belonging to a cult that has raised the first Saizen up to a godlike status. Her words are considered near-holy and her practices likewise. The first Saizen worked for peace, and so will my character. Much like ye olde shaolin monks and many martial artists today the character will use martial arts 1. as a form of exercise and meditation and 2. if there should come a need for violence, they'd be able to it swiftly and efficiently with a minimum of force. 

I therefore ask, am I allowed to make shit up about the first Saizen? Things like what she has said and done and what kind of techniques she uses. 

Of course, it is entirely up to the GM to both monitor and decide if the first Saizen actually interacts with her cult in any way or if it is all the minds of the cultists.