Funny how I've seen some people take her reversal shtick so far that they believe that she always says the opposite of what she's thinking for the
sole sake of being a contrarian due to her being an amanojaku. But isn't she more of a normal trickster in canon?
That, and the entire Gensokyo ganging up on her to exact revenge (breaking the spell card rules no less) seems too far-fetched for me. The DDC youkai rampage incident wasn't even that serious compared to earlier ones, and that's the first time we've seen that severe of a reaction - Tenshi got other people gunning for her in her story mode, but that's because she leveled Hakurei shrine and caused weather anomalities, meanwhile the rest always got away scot-free and even got invited for tea, including Remilia, the queen of selfishness who spread poisonous mist around to walk outdoors without a parasol. If Gensokyo actually
is so big on the "might makes right" idea that being one of the powerhouses is a prerequisite to being granted forgiveness (assuming you don't cause trouble any more), then I can kinda get behind the notion of a social upheaval in Gensokyo.
The big question here: is Seija an Aya or a Sanae?
I kinda wonder about your definition of "an Aya" or "a Sanae", but if you mean the pattern of transformation into playable characters, then she is definietly Aya 2.0, as she got her own game after her initial apperance in order for ZUN to expand upon her character, giving us some alternate spin on danmaku on the side. Sanae is more of a Sakuya 2.0, having only joined as a
youkai exterminator and an
optional character in a
main game, as opposed to a spin-off.