I, the Weakest Traveler, Start by Taming the gods of the Old World. - Chapter 64: Yandere prisoner

The next morning, Jian Anning asked, “What is happiness?” Yu Xingxing hooked his lips into a smile and suddenly pulled her into a tight embrace. “Happiness,” he said, “is being with the one you love and doing things that make you happy. Let's continue, wife!” Jian Anning kicked him off. “Get lost!”

Lin Tian, who had reincarnated into the world of One Piece ten years ago met Garp, who was on duty to eradicate pirates, and become his student.

Year 2056, in a city in the Yuan Jiang Su Jin area. On top of a ruined, shattered six story residential apartment sits a teenager wearing a combat vest, militaristic trousers, and alloyed battle boots. On his back is a hexagonal shield and equipped is a blood-shadow battle knife. He sits there silently on the edge of the roof. At this time, the sparkling sky was shining and there was a refreshing breath within the air that blew towards him. However, there was only silence within the ruined, deserted city, with an occasional howl that makes your heart skip a beat.

- Description from novelupdates

“I hate this world. I hate everyone. There's no justice for the weak,”Once happy and carefree, Reign's life took a dark turn when he was kidnapped and undergone brutal experiments.These trials broke not only his physical body but also shattered his mind.In the end, his body couldn't withstand the ordeal, and he died like a pitiful lab rat.But death wasn't the end.He woke up in a new world as a corpse, armed with the Ultimate Mutation System.A system that enabled him to mutate and gain power in exchange for his own humanity.Determined to avoid being exploited again, he sets out to become a true powerhouse.He knew that being weak would only make him a target, especially now that he was a monster.“Kill or be killed.”That was his only option.