Demon Keeper is a Manga/Manhwa/Manhua in (English/Raw) language, Drama series, english chapters have been translated and you can read them here. You are reading Demon Keeper chapters on https://mangabtt.com, fastest updating comic site. The Summary is
The hard-working programmer Qin Jian died unexpectedly after working for several days. His soul penetrated into Qin Jian, the county official of Sanyuan Town of the Tianyuan Dynasty. He has the ability to recognize demons with the Heavenly eyes but because he sleeps with demons all day he was contaminated with their breath which caused a misunderstanding by the demon hunter and the demon clan to be a demon… The sin demon, the good demon, the beautiful demon, etc. The rookie started his fantastic journey of becoming a Demon Keeper.