How did the demons trick the divine plane? Why are there demon dukes in the army? Why are the demon dukes bowing to the high-rank demon? Where is the demon king that they should be bowing to? What do Helios and Stelios plan to achieve with the demons? So many questions and so few answers?
All of it reeks of an insidious scheme and he is sure a demon king will show up soon. His suspicion is not baseless paranoia because when there are demon dukes, there must be a demon king. That demon king might even be in the mortal realm right now. It is unlikely but just because he hasn't seen the demon king yet doesn't mean it is not around. Even if it is not around, it could be on its way.