During the destruction of Buddhism at the end of the Incense Era, the high level monks of the Buddhist Sect created a desperate plan for the future of their religion.
While one group supervised the ceremony to call a higher being inside the Western Pure Bliss Land and lure the Absolute Beginning Emperor inside, another group had another plan or mission. The upper echelon of Buddhism knew that as an Eternal Emperor, the Absolute Beginning Emperor would not die at the hand of the higher being, however being severely injured was more than enough for them.
Taking the short breathing time that they had, they hatched a hasty plan: they chose someone to survive this calamity and one day revive Buddhism. However, in such a short time, no one actually had a real or feasible plan, so the upper echelons decided to find a way for a person to live long enough to accomplish this task.