A) He is probably the younger brother/nephew/son/cousin/little uncle/ of that white haired villain who have wiped out the village where Physician Mhan lived
B) He is the villain and shrunk himself (it's wuxia and there might be pills that can change body figure) to keep up the facade in his family
C) Just some cliche creepy frick who have no respect on personal boundaries, the type all smile and acting shady
My guess about the white haired brat:
A) He is probably the younger brother/nephew/son/cousin/little uncle/ of that white haired villain who have wiped out the village where Physician Mhan lived
B) He is the villain and shrunk himself (it's wuxia and there might be pills that can change body figure) to keep up the facade in his family
C) Just some cliche creepy frick who have no respect on personal boundaries, the type all smile and acting shady