The Number One Undercover Agent in the Fairy World

I, Lin Yun, have an excellent foundation. I thought I would be trained as a key disciple, but... "The Demon Sect would never have imagined that we would send such an outstanding disciple as an undercover agent. By then you will be in a high position in the Demon Sect. We should cooperate inside and outside. Why worry about the Demon Sect not being destroyed?" Three years later. "Zhengdao would never have imagined that we would send such a potential disciple as an undercover agent. When the time comes, you will be in a high position in Zhengdao. We should cooperate inside and outside. Why worry about the righteousness being destroyed?" Lin Yun: I just want to become an immortal quietly...