The Clan Master Can't possibly Be A Mortal - Chapter 33 - Siege on the Centennial Tree Demon

Having been reincarnated, Shen Changqing became a member of the Great Qin's Demon-Subduing Division during an era infested with Demon Evils and rampant Strange Monsters—After slaying a Ghostly Level Fiend, his Pure Yang Technique reached Perfection!After slaying a Resentment Level Monster, his Heavenly Martial Gang Qi reached Perfection!After slaying a powerful Demon Evil, he broke through his own limits!After slaying—Years later, Shen Changqing became the Defender of the Human Clan, and all sorts of Demon Evils and Strange Monsters bowed their heads in submission!“As long as I live, the Human Clan shall not perish!”

A martial art expert from the Song dynasty lives like a Phoenix that can live again in another body after death. This time, he happened to take over the body of a Japanese high schooler who is also a victim of bullying and has a bit complicated family circumstances.

- Description from Novelupdates

Yang Feng somehow transmigrated into a different world and received a legacy of an ‘ancient high tech’ family, which does not directly raise his power, but gives him the technology to build things which are way more advanced than the seemingly medieval world.

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.