Prince Ao Li
A couple of things about Prince Ao Li make me suspect that Cheng'en was quietly alluding to the presence of Sogdian culture during the Tang Dynasty. Ao Li actually appears to be taken from central and west Asian dragon myth. Firstly, having fiery breath, and secondly swallowing Tripitaka's horse. Having written his novel during the Ming Dynasty, could the author have been alluding to the western-derived Manichaeans and their later influence in the White Lotus Society, which had been driven underground after the Ming emperor decided they weren't of use to him anymore? Another thing that makes sense about this ide was their choice of words in naming the "Ming" dynasty, which certainly resembles the naming of the Mingjiao/Manichaean religion.
Following that vein into the following dynasty, could the Tiandihui have been descended from the Wite Lotus Society, or did they perhaps just borrow from their rituals and revolutionary jargon? Because it also appears that the design of the flag they backed during Sun Yat Sen's revolution (now the Taiwanese flag) looks a bit like a white lotus.