MTL - Heaven’s Will Balancing System - Chapter 114 3 thieves

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’.

Before Wufu was reborn, she had no idea there was such a thing as rebirth. Only after her rebirth did she realize Heaven must have thought her previous life was too smooth, so it sent her to suffer in this ancient land where morality, decency, and the Female Precepts were held in high esteem, pitiful indeed! From being a master jade carver to having her soul transmigrate into a farm girl with a wretched background, she was bullied and humiliated. Even the bun-selling mother advised her that forbearance is gold? Bullshit! She could endure, but her other identity absolutely could not—robbers, swept away; insults to her mother, you're crippled... Wufu has a saying, for every insult and humiliation, I will repay a hundredfold. But what's with this one? He doesn't bully her; he only wants to sleep with her? And he even dares... to mount her? Well, a lord can endure, but Wufu cannot. Mount him back, life or death, a hundred years, neither owes the other anything!

Our protagonist Caam is a man from Earth that was reincarnated into this world as a demon. In order to survive, he spared no effort in avoiding the sparks of battle and without noticing it, he became strong himself.

A boy wakes up with omnitrix as a X-GENE