Well I just beat it, and I admit, I used save states for the final boss. It wasn't anything I couldn't do, just not something I wanted to fight six bosses everytime I wanted a chance to memorize how to react to one move scheme.
Anyways, I was thinking about playing the sequel, so I Wiki'd it. First time I've ever seen vandalism in an article, so I was caught off guard.
Nsfw.
Apparently it's hard.