User blog comment:Battlefield4us/Interview with Monty Oum/@comment-5041507-20140711180456/@comment-3146930-20140711204453

Except in Volume 1, the final fight of the volume was against the Roman and the White Fang; who for the most part seem like bigger threats. As far as monsters, we got a big Grimm fight during episode 8, but the Grimm don't really seem like big bads as much as Roman and Cinder do.

As far as a big hint, all it means is that the big bad won't be a robot or monster, but that still leaves plenty of room for other types of villains.