User blog comment:Jkphantom9/Notes from the RWBY portion of the ExtraLife Stream/@comment-11188061-20151110015241/@comment-226878-20151110050947

An high-powered Grimm as the Final Boss could work. It's still not a villain though. It's just The Dragon to the Big Bad or Bigger Bad. Admittedly, I can't think of many examples of The Dragon as a Final Boss other than Final Fantasy X.