They literally gave Kayblis the best ending possible, with literally no future opposition to stop him from ruling the continent in a few thousands years when he manages to reach and surpass his power level since there’s no more demon king, the gods have a non-interference policy, all the dark-lords that weren’t sealed being turned back to their original species or killed and no new ones being created. Rance’s children’s children should have their level caps turned back to normal after many many generations as it was an anomaly in the first place so he doesn’t have to worry about that either…