I Possessed a Demon Sovereign - Chapter 646 - : The Reopening of the Imperial Mausoleum

This book is about baby-making.

As the last abyssal demon in the world, Wen Long was pulled into various worlds to do tasks by a guy who claimed to be a system. The goal of her mission was to save those villains who had been blackened for various reasons…

- Description from Novelupdates

The consciousness of a Great Magus suddenly returned to his original body on earth, just before he transmigrated into the magic world.

Nothing has changed, it's still the same earth.

However, when he looked at earth once more as a former great magus, he discovered earth was not as simple as he knew it to be.

Hidden magus, legendary races such as vampires and werewolves, they do exist, ruling the world through the shadows.

Faced with a former great magus, who possessed as many spells as libraries, would the earth that had been ruled by a few people be able to remain calm?