Iason Heine:
Um... I'm not sure about the Emperor's Prayer but the Witness of Dawn... I think that means the one who represents the Lords of our Dawn.
I'm sure you've heard of him. His name is Franz. In fact, his official title, now that I think of it, is Witness of Dawn Franz.
But I didn't know that he's aware of the Book of Seals at all... Very strange.
I believe it's best if you ask him about it directly.
But first you should learn more about Franz by visiting Priest Wood in the Town of Aden. Franz is not a man who you can meet easily, but Wood will know his whereabouts. Don't forget to mention my name when you meet him -- he will be much more cooperative then, I'm sure.