Hwansaengmasinjeon

The Young Heavenly Demon, Yeon Woonhwi, attained the position of cult heir in the Heavenly Demon Cult with only supernatural abilities. His life of chaos finally meets its end during the rebellion of the vice cult leader and the elders. [Even if you needed to kill me, you should have remembered what kind of man I am. So, all of you, die!] After dying together with all the traitors, he wakes up in a place he could never have imagined. [A branch of the Tang Clan?] Tang Woonhwi of the Sichuan Tang Clan's Nine Dragon Branch Family now dreams of rebuilding the Heavenly Demon Cult!

(Source: KakaoPage, translated)