You feel pity for me? Good grief, you have an operatic life. 8P
The idea of a corrupting book is not new, btw. I've sold versions of it to Atlas twice, and I was just copying the idea from Jeff Tidball (?) who flogged it to Lion Rampant back in the day.
We were, I thought, talking about writing Tribunal books. As many times as I've tried suggesting that canon is for authors and the rest of you should ignore it, the community and the owners of Ars Magica insist that, no, actually, canonicity matters. That means that if you establish things, you've established them. There are various dodges, like the unreliable narrator in Covenants, like saying the word "covenant" means different things to what's expected in AtD, but basically all of your colour text is how the world really is. People who buy your book don't want to later by a book by someone else and find a bit which says "Yeah, ignore that bit from Pralix." That's only ever done in the case of mechanical errors (some of which were mine, like the crossbows.). That's just one of the ground rules of playing the game of being an Ars author. It's not negotiable. It doesn't matter how "daring" or "creative" you are if you refuse to produce product to spec, and part of that spec is that colour text is canon.
For authors, canon matters. It's not about lacking "the will to create something new" - it's about having the professionalism to deliver something within the actual constraints of a real project.
It would be great for an SR article, though. You should write it up.
If the book was written by a demon, then you have a demon who breaks one of the fundamental rules of being a demon. Demons are incapable of persistence, because it requires patience, which is a virtue. They can have mortals do things which require patience for them, but can't have patience themselves. So, writing a book is probably beyond them, unless they can mystically birth it in an instant. Also, it means you have a demon who understand Hermetic Theory. This was possible in 3rd edition, where infernally tainted people could become demons. I'm not clear on how possible it is in the current edition. Certain odd demons (the Watchers) supposedly can teach chthonic magic, so...maybe?
You misunderstand my core point, though. This idea was first sold to LR back in 2nd edition "Order of Hermes". Tsagilla spread books that forced personality change through the rest of the Order. Since then, that's been mentioned several times in later works. I've not yet read Faith and Flame (my copy was delayed), but it's in AtD, for example, in that there's a library of them at Ceoris. When I say "If you want to stat them up this way you need to..." I'm not randomly spouting ideas. I'm saying "The reason you do not have stats for the Red Library in Ceoris is because we are not saying how Druidcal magic works. The reason you don't have stats for the Black Library which includes the books circulated during the Tsagillan Corruption is because it takes up huge amounts of space we'd like to use somewhere else."
If the book were indeed written by a demon, why hasn't it been destroyed? This plot hook's not new: it's so old that the layers of response the Order has to just this situation have already been detailed in other books.
I think this proves my larger point. You've just crafted a book, and the obvious stories it provokes are ones which are already in the line.