A large, hulking woman, Sakura claims to be the "strongest person alive", and we have no reason not to believe her. It's not so out of the question someone like her could be a killer, right? Although she is very kind and caring, seeming protective of those around her, especially those that are unable to protect themselves. 

You do not have to audition as both the voice and singer, though it is preferred! 

NOTE: I can only imagine how difficult singing in her voice will be, so if you need to lessen some of her rasp, I'll allow it. Whatever you can do it make it work!