Don't get me wrong, I don't think that lady is a "bad" character idea, it's just that I found that boss battle easy but very annoying. If she was less annoying then maybe. I don't think as a playable character though due to her lack of melee combat skills.
Sorry it's just that of all of the DMC Heroines, she is the least heroic. She is just thirsty for demon blood, arguably making her as much of a psycho as Arius, Mundus and her father.