Alright... their leader is named Yuewei Xiaolan... I think that's a reference to this guy
https://en.wikipedia.org/wiki/Ji_Yun
Because he's called Ji Xiaolan and he this https://www.amazon.com/Shadow-Book-Ji-Yun-Knowledge/dp/1953124011/ref=sr_1_1?dchild=1&keywords=the+shadow+book+of+ji+yun&qid=1628789386&s=books&sr=1-1
which is the Yuewei Caotang Biji