Responses
Based from what I understand, Bai Jing divided his spirit root into two in Quishan to remove Mr. Bai (demonic aura) from himself. Since there are demonic force there, Mr. Bai successfully obtained freedom and his own body from the half of the spirit root given to him.
He (Mr. Bai) was also the one who gave Yin Hong the Heavenly roots to cure Bai Jing.
Wait?huh?when did mr.bai separated from bai jing?wth?i'm confuseee?does mr .bai reincarnated inside Qishan?omg so many plothole this story.