My guess to all this - this is a prequel to Immortal Regis even (the true sequel will start soon, maybe next volume)

Read the last chapter or 2 of Immortal Regis - Depore chose Jae Hyuk because he had "light that enveloped others", she chose him because he wasn't selfish and he cared about others (the opposite of Nex, who only cares about himself).

Also, remember in IR that everyone knew magic - here, magic seems reserved to a few key people, with everyone else using weapons - this suggests that there's no school of magic established like there was in IR

Also remember that Navarus, in Immortal Regis, went all out to save Serin, saying that there was no demon clan without her - maybe the serin we see here is IR's Serin's mother?

I think what we're seeing now is an older story, the story of how Noches originally fell from power and Depore was sealed in the tower of Soul Wrenching Agony (it seems Rukretius was sealed in the tower by Orkis as well).

I amend my previous statements. These most recent chapters have been quite illuminating.

This signature was recovered from Hades to serve in my rotting armies.

when will the next chapter of cavalier of the abyss vill be coming