Alright this is a really farfetched theory but something just struck me. Could Master Baihu actually be Zunming Zhao?
As crazy as this sounds there are quite a few things that make is seem plausible.
First of all, Master Baihu completely hides his idenity with a mask and heavy face paint that, with the addition of the vicious red eyes give hima "ghostly" appearance. Second, he uses Tiger Swallow Style, the same style Lan Di uses.
Third, he is almost the same height as Lan Di (only 2 cm shorter) and he has even has the same blood type.
And lastly, his age is unknown, that always smells fishy. Of course he would probably be in his mid 50s if he really is Lan Di's father but it would be possible, with the mask and paint on his face he could easily hide his age.
What speaks against it is that Ryo could defeat him so easily and that he didn't recognize his appearance or the Hazuki name at all. But maybe he lost his memory (minus his fighting style?) during whatever happened between him and Iwao, was thought to be dead for quite some time and then then the Yellow Heads or someone else found him and "revived" him to what he is now.
What do you think?