Harem System: Spending Money On Women For 100\% Rebate! - Chapter 4: System Upgrade!

Reincarnation.A concept everyone is all too familiar with, at least once in our lives, we've all thought of being able to just let go of all our regrets and the things holding us back and just start over.This deal is made even sweeter when paired with being allowed to keep your current memories and knowledge of the future.William was one such boy who had been given this once-in-a-lifetime opportunity.Like any other modern-day person, the first thing he did after learning about his reincarnation was check if he possessed any memory that was similar to his new world.Sadly, in the end, he was left disappointed and was forced to go into his new life completely blind and unaware of all the malicious entities, world-ending threats, and divine schemes going on in the shadow.But then again, who needs knowledge of the future when you are the child of mana itself?

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

Xu Yangyi, an 18-year-old high school student, for the reason that his older twin sister eloped with her girlfriend on the wedding day, was forced to be the surrogate bride by his own father. As a result, he became the wife of the man who should have been his brother-in-law.“You’ve gotta look at me carefully. I’m a man.” Xu Yangyi glared at He Jingyan, who was still getting fresh with him though he already knew Xu Yangyi was indeed a man.“Man?” He Jingyan fiddled with Xu Yangyi’s face with his big hand and gave him a sly smile, “You look identical with your sister, so it doesn’t matter!”