The Eunuch is Pregnant - Chapter 13: The King of Hell is savage!

Traveling through time, he became Zhang Gui, a foreign relative of the Tianqi Dynasty. Because he didn’t want to be tortured to death by Li Zicheng in the future, he had to embark on the road of harming the powerful and bureaucratic officials of the Ming Dynasty.

The Yanguan scolded him for coercing the king and making disorderly manners.

The prince scolded him for being greedy.

The official hates him for being mean and cruel.

But helplessly, most of the Nine Frontiers are his lackeys, and even Jiu Qiansui is his godson, and the emperor can’t do anything about him.

Therefore, the Ming Dynasty was at the mercy of him.

- Description from novelbuddy

An ordinary student, a wretched peeper, a cowardly teenager with a kind heart. In a terrorist attack, he inherited the knowledge of countless elites, embarked on a path of God Jagged Tu…

He is an artist!

He is a mathematician!

He is a psychology Doctor!

He is a master of fighting!

In fact, he is a man

Taken off raw site:

A wretched, dirty young man is working during the summer when he was caught up in a mysterious explosion. After that explosion, the young man is then left with the memories and knowledge of dozens of the world’s experts.

He has changed, his heart has become cold, iron-blooded. He became a killing machine, his mind turned mechanical, calculative. Everything goes according to his plans and calculations!

In this magical, slaughterous world, a door is opened for him…

- Description from Novelupdates

The world is terrorized by the powerful Black Witch who has been sealed in the moon. Every ten years, the night of Hexennacht arrives and a chosen witch must battle the Black Witch in hopes of finally defeating her.

As the current decade’s Hexennacht approaches, a mysterious girl named Kagami Kagami arrives and meets Horinouchi Mitsuru, the daughter of the previous Hexennacht representative.

It takes place between Kyoukai Senjou no Horizon and the City Series, two other series by the author.