is she not op? guess I should keep on reading this a bit, kinda disappointed

She is though. Literally sealed away the Demon King who the hero party always had trouble defeating. The only reason why she couldn't kill him was that there had to he a demon king in that world and the powers of plot forbids her from killing him. Otherwise, her pure hatred for this world would wipe him out with a Thanos snap.

If you're talking about some of her chapters with Duke, she was putting on a weak facade to trap him. The awakened are still powerful so she's gotta be a little more cunning if she wants to torture them.