Now, the interesting thing about Byakuren, is that she wasn't always the sanctimonious goody-two-shoes that we know and hate (or love). She (and most of the Buddhist cast) have more developped characters compared to the rest of the touhou girls.
Murasa was a cursed ghost that was freed and became okay (through it's rumoured she has a drowning fetish), Nazrin is an underling that everyone shits on, but is really Bishamonten's trusted little mouse. Byakuren started as a hypocrit bitch that didn't want to die like her brother, and ended up as a nun leading a Buddhist temple and spreading a false religion.
If only the rest of the cast was as interesting as her, it would be awesome.