What does this passage in the Water Margin mean? What is the meaning of the obscure Taoist Emperor of Jade Qing?

It's Song Huizong. This guy believes in Taoism, builds temples, calls himself the founder of Daojun Emperor, and often invites Taoist priests to visit fortune-teller.

In A.D.11/7, Song Huizong was bewitched by a Taoist priest, saying that he was a fairy of the Yuan Dynasty, that is, the leader of Jade Qing, and gave himself the title: Jade Qing concealed the Taoist Emperor.