Although Xiao Mu Bai was only an imminent World supreme powerhouse, he was the face of the God Defying World. He was usually responsible for liaising with powerhouses from the Outer Boundary and the Myriad Worlds.
The World supreme powerhouses and Saints from the Myriad Worlds and Outer Boundary could not easily contact Duan Ling Tian and Feng Qing Yang. However, they really wanted to form a good relationship with the duo. As such, they would look for Xiao Mu Bai when they visited the God Defying World.
