Yuyao Guo (御妖国) was a Kingdom in Beishan and home of the Yuyao Princess.
Yu Yao means 'Manipulate Spirits'. Indeed the Yuyao people were able to command yaoguai to their bidding using Zimu Fu.[1]
However, after Yuyao Princess and Shi Kuan helped free the yaoguai from their bondage, Shi Kuan became the new emperor of Beishan.