You're mistaking me for someone else.
I'm the one thinking she's both. On the outside, she's a "benevolent" figure trying to spread her religion of tolerance. But inside her heart, she enjoys abusing her authority and doing whatever she wants without thinking of the consequences.
After all, the rest of the buddhist cast looks up to her each time they have problems, but what can Byakuren do when she's the one having trouble? Pray to Buddha? We all know that praying doesn't fix anything on the long run, you may feel better, but the tentation will come back.
And not only that, but perfection is tiresome. I'd rather have a conflicted Byakuren who spanks her disciples when they're doing bad things while repeating herself that it's for their own good but never admitting she's deeply enjoying that power she has over youkai over the perfect Byakuren that repeats "it's not nice to eat people".
Conflicted characters are more interesting than perfect characters, and a Byakuren torn between her desire to be good and her desire to dominate cute little youkai is more interesting than a perfect Byakuren that can always control herself and doesn't even know where the dick goes and cleanse your thoughts just by standing here.
And my boner is happy when I read story about character developpement that are actually good. Nothing worse in my opinion than a story that ends the same way it started, because it means that everything that happened during the story doesn't have any consequence on anything at all.
Byakuren spanking youkai and trying to get rid of these dark fantasies of her while the Myourenji crew doesn't understand why she locked Kyouko in her room instead of spanking her as usual would be an interesting read. Too bad most fanfic writers would rather write "muh OC in gensokyo with muh waifu".