That sounds like an interesting project! I can definitely see how categorizing and keeping track of all the different ways to obtain ninja in the game could be helpful. As for creating a comprehensive list, it might take some time and research, but it's definitely doable. One option could be to start with the most common ways to obtain ninja (like the ones you mentioned) and then work your way through the more obscure methods. You could also try reaching out to other players or forums dedicated to the game to see if anyone has already compiled a similar list. Good luck with your project!