Responses
I think it was more about Halceles having helped to seal the demon, so the demon was not a fan of him. Hence why Val went demon form and attakced Halceles as soon as the Time Insect's barrier went down.
Obviously the key of all the story is in the past, I agree with you. Both Halceles and Rimris were present so it seems they could explain many things...
Can it be that is Halceles the key to understand everything? I mean: In the last chapters of the first volume Demon Val escaped from his cage when he listened at the name of Halceles, he was feeling pain in his heart. What kind of relationship did the King (Val's ancestor) really have with Halceles? We know that the King had a sexual relationship with Rimris (to increase divination powers, I remember).