User blog comment:Zathronas/Speculative author: Where are the Grimm?/@comment-23790511-20140914035557/@comment-23790511-20140914044038

We do know that they have no souls, no aura, no semblance, but seem to act in animalistic pack intelligence. We know that they appeared shortly after the dawn of humanity and attacked for some reason. Perhaps the primeval humans ticked them off somehow. We also know that they're arguably the dominant species of Remnant still, but advances in human tech have made this fact less known if Port is to be believed.

I think it's more likely they'll talk about Aura, Semblances, and humanity. Then the Grimm, then the Kingdoms. I dunno, it's much trickier to predict a documentary...