MTL - Urban Evil Doctor - Chapter 5172 Yamanaka Shinsou

I found myself lost in a different world, the characters I once read about in web novels were in front of me, harassing me, ruining my damn day. Also, a shitty system that asks you to do strange quests. But you know, the only good thing about all this: I have a beautiful face, it's nice to look in the mirror... ha, ha... I'm going crazy! How the hell am I going to survive in this damn world?tring![System Notification]- [Mission]*Participate in the NOVA Academy entrance exam[Compensation: ??][Failure: System loss]

Doomsday comes, and human beings enter the heavenly world.
Ten years later, Yang Chen, who was betrayed tragically, returned strongly with the Tianyu bug. In this life, he vowed to make the betrayal pay the price. He has a powerful bug bonus, just like an open hang. Frightened to hear…

- Description from novelbuddy

The strongest Hero in history, Nakamoto Keisuke.

He was summoned to another world in the spring at the age of fifteen years old, and when he successfully defeated The Demon King, he was already thirty-two years old. He had finished his role in another world and returned to Japan, but the reality that had been waiting for him was, “Middle school graduate with seventeen years of blank period” label. He couldn’t find a decent job and had no choice but to spend his days working part-time.

Before such a Nakamoto, a beautiful girl who self-proclaimed had come to return the favor, appeared. “I’m the reward for Hero who had defeated Demon King”, said Angelica, a girl who came from another world that persistently tempted Nakamoto to make her his wife. Together with a high school girl who looks like Elsa, his beloved girl that he lost in another world, Nakamoto with his cheats skills got caught in a harem life.

Among the demons, the supreme ones are called “Great Saints.”

A young man leaves his mountain village and travels around the world. By unceasing efforts, he finally becomes a legend of the age.

- Description from Novelupdates