The synopsis gave the impression that Kai had been imprisoned for quite a while, however, it was revealed that he's only been asleep for a year. 

We are also dropped into the middle of the story and are expected to learn as we go along. Usually, I have no problem with this but I got 50% and nothing of substance was revealed. Kai needs to find some missing characters or there will be negative impacts on some meeting . . . . and? What happens if the meeting fails, what are the real stakes? 
Also, Kai is neither a Witch nor a King he is a demon and tho he is a prince in one demon realm, he doesn't seem to have much power over the other demons and the unique powers he has are okay at best.