MTL - Empress True Colors - Chapter 21 jealousy?

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

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

Akira, was born in the slum and wishes to get out but the only way he could was to risk his life in these ruins as a hunter.

Xuanyuan was reborn into a strange new world where training to be a Xian was a cornerstone. There was however something ancient dwelling inside his body. He could now devour all of creation…

This is the journey of an ordinary boy and his transformation into the supreme being that reigns over all existence! Everywhere he went, he could not help but tie his fate with numerous women. It did not matter whether they were a goddess or a devil…

- Description from Novelupdates