Dragon Ball Roshi - Chapter 112 - : Demon Subjugation (Part 2)

Allen, an eight-year-old boy from a poor family in the royal capital, is living a poor but happy life together with his mother. One day, however, memories of his previous life suddenly come back to him and he remembers that he is in an dating sim game and that the capital will be destroyed by war if he doesn’t do something about it. If this continues, both he and his mother will be killed! With a sense of urgency, he decides to rise to the occasion in order to save his precious mother’s life and save his favorite character, the villainous young lady Anastasia, the only girl he liked in the game, from her all too tragic and ruinous end. This is the story of a man who isn’t even a character in the game, but who strives with his steely determination and uses all the knowledge he has to turn overcome fate!

“Take me in, I’ll do anything you want me to!”

The teenager Long Ao, ten years of silence, was reduced from genius to waste, and was ridiculed and mocked.

Ten years of persistence, ten thousand failures, and finally won mysterious Dragon Seal.

With Primal Chaos Saint Body, cultivation invincible cultivation technique, refining Heaven and Earth, devouring endless stars, sweeping the wasteland! Ask the vast stars, who dares to fight me? Boundless Starry Sky, War God! …

- Description from Uukanshu

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