I agree with G-Ps statement of it not needing to be a battle manga because it really doesn't need to be one.
It would be like if suspicious maid suddenly became a battle manga. Or shark girl oh wait it did
It would be fine for bits of action here and there because of the idea that she was sealed away for a reason. But to dedicate almost two entire arcs to it is....ehhhh? I guess.
I mean it is the authors choice what to do with it since its their story. Doesn't mean I agree with theit decisions.