The Greatest Beast Tamer of Earth - Chapter 447 Astral Seed?

Entering Tokyo in the bubble era, in this strange era, the only familiar ones are Matsuda Seiko, Nakamori Akina, Kudo Shizuka…

- Description from novelbuddy

“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.

The Beast Running Back (RB). From mixed martial arts to football, from an obscure rookie to a superstar sweeping the league, from an outsider who knew nothing to a terrifying beast... He left numerous legends on this field and became a myth that changed the sport, yet at the beginning of the story, the creator of all these legends claimed innocently, Football, what’s that? I’m truly not a football prodigy, really.