Till the End of Time - Chapter 11

She is the legendary queen of mercenaries whose name daunts even the big shots in society. With an ancient jade pendant in her hand, she is great at almost everything, be it seeking the truth or the art of healing.

A con-man and policewoman that are legends of their respective professions suddenly die, then are reincarnated and return to the Tang Dynasty of ancient China as little kids.

Accepting their second chance and forced restart, they choose to use the modern knowledge and specific talents that they have in their previous lives in order to live comfortably in this new life.

- Description from Novelupdates

'Confucius spoke not of the bizarre, the valiant, the rebellious, nor of spirits and demons.'This is the story of Mok Gyeongwoon, AKA the First Heavenly Demon - Cheon Ma, the forefather of the main character of the popular novel and manwha Nano Machine. This story is the prequel to Nano Machine, taking place 800 years earlier.

A 30-year-old NEET is reincarnated into the body of an otaku that choked to death on instant noodles. As he comes to grips with his new life, he realizes that this world is subtly different from Earth. The denizens of this world are far better looking, and this new world also possesses futuristic technology as well as mysterious Yin Yang masters!