Once you've completed Alice's The Snatcher's subquest, Mercy will show up in the Final Battle and ask Alouette an important question with no correct answer. There is a simple way to call her out on that, (That I use in several of my games.) That should change things. I'd spell it out more clearly, but I can't figure out how to do spoilers on comments.
It's in the readme/changelog, though.
Viewing post in Angelic Acceptor Alouette: VXA comments
Okay, thanks, got it. That's somewhat obscure, although you are correct that I have used that before in other games, and I don't want to complain about things that I just wasn't clever enough to figure out by myself. I would, however, suggest that section of the changelog explain what you need to do. In fact, I would copy that section into the readme, which is where I looked for it before posing the question (and where I expect most others to expect it).
You are correct that I find that ending much more dramatically satisfying. I do wonder why it is necessary, after entering episode 13, to complete the first ending before you can return to normal gameplay. I also wonder what the in-universe explanation for this is. (Simone uses pure dramatic power to trigger Final Exception without a compact?)
But like I said earlier, this is an exceptionally well-made game. Thanks for it.