War Nishino
another guess, xue xue is Yuer's fiend left when she died, as she remember the fiend had a break through and been sleeping while she is in trouble in the past life... maybe just maybe when Prince Li heard Yuer died he save the beast who had transformed into another form so she can't remember but feel strange yet comfortably safe and since Prince Li save xue xue, the beast form a bond with him... but its original master is Yuer.