The Strongest Interstellar Commander - Chapter 16: Ed Campbell.

[Love After Marriage]In order to avoid an arranged marriage, Shen Yin, the young miss of a prominent household, jumped into the water in protest. When she opened her eyes again, she found that the world had become fantastical. Not only was she naked, but she was also lying in a large white tub. Just as she thought she was dead, she was told that she had a child and a husband. She tried to regain her clarity.

I was the one who boosted your rank. Yet you stabbed me in the back? Fine. Goodbye. I’m taking it back. You’re finished now. Thanks to you, I now have an abundance of skill points for a prosperous hunter life. But… after spending some of those points, the S-Rank is starting to get obsessed with me…?

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- 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