He was a Human with an Ancient Ming bloodline, born in the Soaring Immortal Sect. He was very talented and was trained by Sect Elder Atula. The Sect wanted to help him become an Immortal Emperor, but Dark Crow strongly opposed this idea. Even though his bloodline was thin, it was still there, and Dark Crow had not wanted to give Ancient Ming any chance to resurface.
Eventulally, he severed his Ancient Ming bloodline to become a full Human and chose a title Ren Xian to represent his personality and beliefs. He gained Dark Crow's approval on the condition that the Soaring Immortal Sect would not descend in the Mortal Emperor World for a few generations. This was to prevent a resurgence of the Ancient Ming rule in case any of Ren Xian's bloodline remained and tried to use his prestige as a foothold in the world.
However, his wife and sons later on broke the oath and unsealed their Ancient Ming bloodline.
- Ren Xian most likely ruled before Immortal Emperor Ming Du, because his children were still relatively young during Immortal Emperor Qian Li's generation who ruled after Ming Du. On the other hand, it was established that living for more than one generation is impossible without halting longevity (that's why Black Dragon King who lived for three generations is dreaded). If Ren Xian's children were still young during Immortal Emperor Qian Li's generation, then they should have been born right before it, so Ren Xian should have been an Emperor right before Qian Li and author probably forgot about Ming Du.
- Ren Xian is one of the few inhabitants of the Nine Worlds who had successfully ascended to the Tenth World.