Ah, yes. I never give enough weight to SanaeA's story because I only ever played that game as SanaeB. Whoops!
Sanae B's story is more interesting anyway. Her two different scenarios in that game say a lot about her, and a lot about youkai hunting.
I used to hate Sanae. I thought she was annoying, strident, one-dimensional and callow. However, ZUN puts time into the backstories of his characters for a reason. Consider the fact that on the one hand, Sanae was born into being the descendant of a goddess, at a young age discovered she could create miracles, and very quickly ascended to de facto goddesshood herself upon entering Gensokyo - and that on the other hand, she is a young modern Japanese girl, born and raised in the outside world; someone
who read magazines about UFOs, thinks that
stories about youkai umbrellas are "old fashioned" and
references 80s horror movies.
In other words, there's going to be arrogance, haughtiness, and contempt, but also a lot of normal young modern girl in there.
Sanae A and Sanae B show these two sides of her. Sanae A is mostly the powerful goddess of purification, faith, and fealty. Sanae B is mostly the goofy kid. There are aspects of her childishness in A and her power in B, but I think that's how it's laid out for the most part.
So it's very easy to sympathize with Sanae, even if you don't necessarily agree with all of her behavior - you understand why she's doing it. As you might expect, too, she does begin to grow up eventually. I think Ten Desires showed a more socially responsible Sanae. In her entire scenario, not once does she instigate a fight - she is merely investigating what's up with all these divine spirits, and each boss she meets attacks her; Sanae, on the other hand, never seeks a fight and at one point even
declines an offer to fight. She fights all the same when challenged, of course, but Sanae's growing up.
Is she losing her edge as a youkai hunter? Maybe, but for what it's worth I think she's realizing that keeping the peace and maintaining plenty of faith for her Lady can be achieved through means other than pure youkai roid rage. She succeeds in Ten Desires through an approach of looking out for the well-being of Gensokyo (and of course, her faith) but only fighting if provoked. Not exactly the rip-roarin' "EXTERMINATE ALL YOUKAI!" Sanae of UFO.
Maybe she's not the BA youkai hunter she once was anymore, but I'm alright with that. It's interesting seeing a character grow and change over time.