I Just Wanted to Get Out of This Possession

I possessed the body of the master of the protagonist in a martial arts BL novel titled <The Descent of the Heavenly Demon>. And the novel begins with the protagonist, Cheon Rang, losing his master. “No, no! Master, Master...!” “...Rang. You must... be happy.” Though it was heartbreaking to part with the disciple I had raised for nearly ten years, I thought I could finally return home. Because I had fulfilled my role as the protagonist's master, ‘Man Yu-kang.’ However... “...How are you still alive?” I opened my eyes in this world once again. And this time, as a character I had never seen in the novel, someone named ‘Dang Baek-seon’! I have no idea why this is happening. Where exactly di...