The Dignified Young Master of the Demon Sect Wants Me to Be an Undercover Agent in the Righteous Way.

The most ruthless young master in the demon sect was sent to the first sect of the right path as if he were dead, disguised as an outer disciple with a poor background and ordinary bones. He originally wanted to subvert the righteous way and slaughter the immortal sect, but over the long years, he was completely changed by his gentle, powerful and devoted senior sister. Finally—— He gave up demons, kept the Tao, protected his senior sister, and brought peace to the world. The senior sister became the co-master of the righteous path, and he became the only emperor in the world of immortality. The two worked together to suppress the turmoil in the three realms and ascended to the upper realm together.