User blog comment:Zolnir/Cinder Fall (Part Two)/@comment-9090085-20140607040312

... It might be that Cinder has a second soul inhabiting her body alongside her own, but that has "adjusted" to her rather then just try and assume direct control(notice that both of the "Auras" coming out of her are flame shaped; compared to Ruby and Pyrrha, whose red "Auras" are rose petal-shaped and maple leaf-shaped, respectively).

I guess what I'm trying to say is Cinder may be... corrupted by an entity that has taken up residence in her "stable", and has enhanced her Aura and/or Semblance to the point that she feels she doesn't need a weapon; all while subtly manipulating Cinders' actions(like, say, taking whatever legitimate grievances she has with Remnant's society and blowing it out of proportion).

What said entity is, I have no idea - as you said, it can't be Grimm; they have a body but no soul...

Unless...

If we assume there is guiding force/being behind the creatures of Grimm, then this thing in Cinder may be an opposite but equally incomplete creature to the Grimm: something with a soul but no body; and created to fulfill an opposite role, similar to the Vraals and the Ols from Deltora Quest; one is a formidable warbeast, while the other is a shape-shifting infiltrator... Only what's in Cinder is parasitic rather then face-steal-y.

... Or might she have "absorbed" the soul of another person, possibly one who was dieing? Whose death may have put her on this war-path to begin with?

... Or something else?... what do you think?