The Book of ProphecyFollow

First, we have no idea who wrote this. It is probable that his family did not survive the Epic Cataclysm. When is an easier question, as Moment 1 makes it clear that he was writing it as the Cataclysm was happening, or minutes before.

Moment 1 goes on to describe the Epic Cataclysm. It tells us that only 10 Empyrean Lords will survive, as came to pass. It also implies that Aion (The Will) goes silent at that time. This might also be implying that the priesthood has been lying to us for 800 years, as they no longer truly hear The Will.

Moment 2 pretty clearly tells us that the Elyos (Light) and Asmodians (Shadow) will go to war with each other, which has also happened.

Moment 3 seems to be a direct reference to us, the player. Surely we are the Dreamer. But the next line is one of the most troubling, as it refers to "The Thirteenth". Now, there were originally 12 Empyrean Lords, or so we have been taught, but this may be saying that there have always been 13. If this is true, the Thirteenth must have stayed apart from the others, and they did not know he existed. It is also possible that the Thirteenth was new, created in the moment of the Tower's destruction, perhaps as Aion's last desperate act before His destruction.

There is another possibility, that Aion was even trickier and the Thirteenth is a Daeva that does not, yet, know that he is the Thirteenth. Perhaps requiring some special event, such as a death beyond the reach of an Obelisk, to awaken. Personally, this is my favorite theory.

The last line of Moment 3 gives us hope that The Will is not gone, after all, but merely unable to return, yet. Perhaps His essence was so scattered by the Epic Cataclysm that it has taken 800 years for him to re-coalesce to the point of sentience? Here is a wild theory... what if the bleeding of Aether into the Abyss that our scientists have noted is NOT the death of our world, but the sign of Aion's impending rebirth? What if He is pulling the Aether back to Himself?

The Final Moment is definitely concerned with our future, with events that have not yet happened. Obviously, the author/prophet thought this was foretelling the end of our world, but I am not so sure.

The first line pretty clearly predicts that we (again, the player perspective) will awaken and discover the truth about ourselves.

The second line seems to predict that the 10 surviving Empyrean Lords will all die, but that in so doing, the "true light" will appear. Is this "true light" referring to Aion, or to our own revelation as the Thirteenth?

Finally, "Aether... shall flow into its proper vessel." I believe this is predicting the reclamation of Aion and his taking back the Aether that he gave to Atreia. What this ill do to the Daevas, I do not know nor can I guess. Perhaps we will no longer need it. Perhaps, unrealized, the Aether has been a crutch all these centuries that we no longer truly need?

One finally possibility is that Aion cannot fully re-incorporate and needs a new form? If this is true, then we may be that new form, and the end of our story may be elevation to or merging with the Godhood.

I do believe that The Book of Prophecy is intended to be a roadmap for our adventure. However it plays out, I am sure that, in hindsight, we will understand that the Prophecy was correct all along.