Villain – Peeking at the Diary, the Female Leads' Personas Collapse - Chapter 109

Civilization is destroyed and records lost. Only Dudian survives in a cryogenic sleep. Three hundred years later, Dudian wakes up and must become Dean to survive. Who can he trust in this world overrun by monsters without and within?

- Description from Novelupdates

Li Xuan traveled through the world of immortality and opened the apprentice system, and both apprentices and apprentices could be rewarded for upgrading.

【Ding! Accepting apprentice Qin Yue, reward you: Innate Divine Power]

【Ding! Accept the apprentice Zhao Tian, ​​reward you: call the wind and call the rain]

【Ding! Apprentice upgrade, reward you: space shuttle]

….

Li Xuan, who accepted a bunch of apprentices, evolved infinitely in seclusion.

Ten years later, the Devil Emperor invaded and wanted to sacrifice the whole world, but no one could stop it. The disciples watched the world fall into despair in pain.

At this time, Li Xuan appeared and slashed a sword against the Demon Emperor under the watchful eyes of the public.

Boom!

The sky fell apart, the invincible Demon Emperor fell on the spot, and the entire dark world was swept away by a sword.

The disciples were horrified. It turned out that the strongest person in the world was actually the master who had been in seclusion for ten years.

- Description from novelbuddy

I, Hyoudou Issei, am a 2nd Year High school student and my age is equal to the number of years I haven’t had a girlfriend. And, someone like me got a girlfriend! I’m sorry buddies, I will walk the path of becoming an adult before you guys! – That’s how it was supposed to be, but why did I get killed by my girlfriend!? I still haven’t done anything yet! Are there no Gods in this World!? And, the person who saved me is the most beautiful girl in my school, Rias Gremory-senpai. I learned the shocking truth from her who isn’t a God but a Devil. “You have reincarnated as a Devil! Work for me!” Lured by Senpai’s breasts and treats, my life as a reincarnated Devil began. So the “Academy×Love Comedy×Battle Fantasy” starts here with just aggressive and worldly desires!

Intellectual Villages are old fashioned rural villages recreated with cutting edge technology. Those villages attract the Japanese monsters known as Youkai.

The high school boy Jinnai Shinobu lives in one of those villages and has a Zashiki Warashi living in his house. He tends to run across Youkai with unnerving frequency and this often leads to trouble for him.