Cheonhwaseogo Daegongja

The soul of the charming and imposing Martial Arts Alliance Leader, Hu-Gong, suddenly wakes up in the body of a young man.
That young man’s name is Beom-Hang. He’s the young master of the ‘Heavenly Grand Archive’, one of the three major archives of the Jianghu, yet he is a sorry excuse of a person.
To determine why his soul has swapped bodies, Hu-Gong begins to train Beom-Hang’s body. When the possessed young master of the Heavenly Grand Archive’s movements are totally different from how they used to be, it starts to attract the attention of the Jianghu…
(Source: Naver, translated)