The story is really well thought out and I enjoyed reading it a lot. Thanks for sharing.
I do however have to agree that the last chapter was a bit abrupt. The combat scene was also confusing, but I'm not certain if you intended that. If you take the time to improve that scene, I think the feeling of abruptness will go.
That said, I must congratulate you to your idea. The way you handled the prophecy is original and as far as I know has never been written before. And I just love stories that proof that prophecies can not be understood correctly before they have come to pass.