She's a Passerby, But Can See the Protagonist's Halo - Chapter 91

When she wandered the border of life and death at the age of three, Cordelia realized that she had been reincarnated into a game she had used to play as a high handed noble girl. A dark future would await her if she fell in love with the Prince. Therefore, for the sake of a normal life, there was no road but to avoid the powerful prince and the heroine…… But just doing that would be boring. She finally was blessed with a beautiful appearance so she resolved to polish herself, firstly by beginning to study herbology…… This is that kind of story.

Kai of the Sorcerer’s Tower is one of the last mages left, barely surviving in a world ruled by creatures of the dark — where the era of mages ended, and most of the lands got contaminated with dead mana. To save his world and fulfil his master’s last wish, he put himself through a forbidden ritual, risking his soul being ripped into pieces to make his way into the past. In an era with abundant mana — an era yet to enter the Golden Era of Magic. Things go wrong, of course, as they always do, and he finds himself thousands of years before the world fell to mana contamination — in the body of a young lord, Arzan. All is not well, though, as the young lord was murdered by someone right at the cusp of a beast wave threatening the territory, while larger threats loom on the horizon. There was a lot to do for Kai to regain his former strength in this time of primitive technology, but then again, he might just be able to change that.

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.