I Hate Systems - Chapter 7: System Fragment

A former sporting rifle shooter genius transforms into the ‘Juvenile Butcher’. While originally supposed to have received the death penalty, he was instead fortunate enough to have entered a secret and highly regarded armed force, throwing himself into the ‘Nirvana Project’.

In a world where martial artists reign supreme, strength is everything. Unfortunately, that logic doesn't apply to a certain Florida Man.

Refined in the nuclear fallout wasteland, Leo was the strongest mutant alive. He carried an alien artifact, allowing him to exchange his lifespan for modern items. After 50,000 years of solitary life in a humanless world, he collected enough lifespan to transmigrate to another habitable world.

Leo was later thrown into a mysterious planet. He soon discovered that his body produced radiation, and it mutated the surrounding plants and grasses. Worrying that he might ruin the beautiful planet, he chose to live in seclusion.

Unfortunately, the local population soon discovered his existence, and a misunderstanding ensued.

As we all know, there is a force that must not be messed with in the Southern Region, thatched cottage.

Among them, the eldest disciple is the Qingyun Sword Master of the Southern Region, with a mastery of swordsmanship.

The second disciple, the Eternal Empress, leads an era.

The third disciple is a great Confucianist in the world, and the star of Wenqu came down to earth.

The fourth disciple, the reincarnation of the demon god, suppressed Jiuyou.

…

Lu Changsheng: Me? I am nothing special, just their master.

- Description from novelbuddy

Xue Xi is forced to fall in love at first sight with this dangerous man on their first meeting. With death being the only other option, she makes the first move: