Black Corporation: Joseon - Chapter 257

A part-time job contract. He became the cold CEO’s imitation boyfriend. He merely wanted to earn a few small bucks and live a comfortable life, but a pity, he was in constant turmoil since then. Well, life had something else for him despite his wishes.“That… beauty, will there be an increase in wages for conversion from ‘boyfriend’ to ‘husband’?”

27-year-old Hisha, transmigrates into the body of a thousand-year-old overpowered supreme overlord who had everything at his disposal, except one–worthy companions by his side.

Hence, a tournament was held to choose the best out of the most beautiful, unique and strong women across the land.

These women don't follow the rule of coexisting women in a harem, they fight for the right to bed their lord and would stop at nothing but to use every opportunity to seduce, and fight on his behalf just to get his attention and favor.

Hisha never liked such a barbaric method of getting a companion.

'Why choose a few, if you can have them all?'

'If he can't have them all, he would try to work out coexisting the strongest for his pleasure and benefit.'

He realizes his 'Desire System' levels him up with every adoration gotten from his harem. The stronger they get, the higher his level and hold in his world.

As he continues to break his limits with the help of his harem, he finds out there are others that threaten his rule and the balance of his land.

'Let the tournament begin!'

Kōdo Ikusei Senior High School, a leading prestigious school with state-of-the-art facilities where nearly 100% of students go on to university or find employment. The students there have the freedom to wear any hairstyle and bring any personal effects they desire. Kōdo Ikusei is a paradise-like school, but the truth is that only the most superior of students receive favorable treatment.

The protagonist Kiyotaka Ayanokōji is a student of D-class, which is where the school dumps its “inferior” students in order to ridicule them. For a certain reason, Kiyotaka was careless on his entrance examination, and was put in D-class. After meeting Suzune Horikita and Kikyō Kushida, two other students in his class, Kiyotaka’s situation begins to change.

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