Started with an interesting premise, built to 'he'll rescue the so-called demon lords and find an answer to this problem' and then within three chapters the demon lords came to HIM, there's now a NEW cause in the 'great power' and...
Nah, screw it, why bother with an 'and'? I'm just dropping this here and now, it's gone off the rails, jumped right over the shark and has nothing sensible to do from here on out.