The President's Pregnant, Ex-Wife - Chapter 455 – What are you going to do to us?

I accidentally changed the whole world, the resurrection of the dead, genetic variation, recovery of the qi, mountain and seas reborn, land and seas expanded and evil spirits have started to appear.

Ghosts are now commonplace. Some people now have three heads and six arms. Some people have obtained martial arts techniques and ordinary people are now just cannon fodder.

Fortunately, I have acquired an ability which can make various items mutate.

books into martial arts or cultivation manuals,

fruits into precious treasures of heaven and earth or poison that you can only imagine and…

weapons, that can split the earth or gain sentience!

- Description from Novelupdates

In the current era, people are either normal or are with ‘special abilities’. Cases related to the latter are managed by the “National Anomaly Prevention and Control and Special Species Management Office”.
Qi Zheng Emperor Sheng Lingyuan was reawakened a thousand years later after he jumped off the fiery Red Lake. Xuan Ji, a newly transferred staff to the Reparations Division of the Deviant Control Office, finds himself having to clean up the mess of a revived tyrannical monarch. The two seemed to share something from the past, but unbeknownst to them, a big conspiracy is stirring right underneath their noses that could destroy the balance of the world.

- Description from Novelupdates

Arthur got randomly transported to another world. Some people would find that terrifying, but not for him, who was tired of his old life; it was an opportunity.

And, after having bad luck all his life, the tide changed.

It was a world of magic where wizards fought side-by-side with their familiars. Arthur got summoned to be one of these so-called familiars.

He was furious. The thought of becoming a pet was not something he liked. Well, that changed when he saw who his master was.

A hot-woman. And, to make everything better, Arthur was inside the Frostpeak Magic Academy, which only had women students.

“This is heaven. All familiars are beasts, but I'm different. I'm a good-looking man inside a place filled with hot girls.”

When he thought his luck could not get better, he unlocked a system that helped him with everything. Of course, he used the system for a greater good, like getting girls.

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.