Devils
"You ask how I know? The question should be, why wouldn't I know? Ever since the recent war with the humans, I have sensed a certain element. You forget that I myself am a demon. We have close ties to devils. You could almost call us cousins. If you ever study the history of demons back before the first war, when life was almost wiped out. You would find that demons and devils once lived alongside each other. At that time, man, beastkin, demons, devils, even gods, and goddesses all lived on this planet. But because of that one war and the intervention of a higher power, things became different. The records do not explain it all, but from what I know, that higher power split off the devils and gods to their own realms, and then the system was introduced." Creige explained.
"Wait!" Sei held her head. She felt like it was about to explode with all this new information. "You are saying that the demons have records of when the system actually came to be?"