Fairy, I'm going to control you tightly!

Ji Nanbei transmigrated to the cultivation world, becoming the junior disciple of a fallen demonic sect. His master was an alcoholic who had disappeared without a trace, his senior brother was being hunted down by the righteous sects, and his only senior sister only wanted to dabble in his misfortunes. Just as he was packing his bags to run away, the "Strongest Demonic Cultivator System" finally activated. The system's function, [Body Possession], was activated, allowing him to randomly possess another person's body and synchronize his cultivation insights. The first possession resulted in a flash of light. Ji Nanbei looked at the aloof and ethereal girl in the mirror, feeling the immense golden core spiritual power within his body, and fell into deep thought. —It seemed that he had possessed that legendary righteous sect's prodigy saintess, who had reached Qi Refining at six years old, possessed twelve golden cores, and was invincible among her peers. Even more outrageous was that this rumored, cold and aloof number one righteous sect member timidly spoke in his mind: "You...can you not do bad things?" From then on, the junior disciple of the demonic sect's life completely went astray. By day, he was a lowly fish in the demonic sect, struggling to survive and cultivating miserably. As night falls, he becomes a righteous prodigy, using his top-tier immortal body to practice the wildest demonic arts, while also soothing the shy "host" within his body.