All horny spanktalk apart, the Buddhists folks are probably the funniest to have around.
Think about it : most youkai are total dickheads and faggots that enjoy stroking their own dicks while repeating to themselves how superior they are, compared to these feeble and weak humans.
A few of them are actually decent, but in most cases, they don't consider humans as rivals, merely as cattles and playthings.
And then there's Byakuren.
She's a nun on top of being a witch, she uses holy magic as well as demon magic (because I don't think that it's a coincidence that her attacks look like Shinki's), and she has youkai that are so loyal to her that they put themselves in danger to save her.
Not only that, but she also seems to really believe her Buddhist bullshit (to a degree).
That woman is a walking paradox. I'm sure that if it wasn't for the fact that she uses magic, she could become a celestial. But then again, without said magic, she dies.
And yes, I think she can beat the crap out of someone if she's pissed enough.