The third and final letter decrypts smoothly to his name.
At this point, you have a large quantity of blood willingly donated by the Korvosan populace. Do not use all of it in the targeting ritual. Using all of it makes the source of the sacrifice incredibly obvious, and even with the resulting power, the resulting opposition will be problematic. Instead, select about one in every five to ten of your donors. This should be a cross-section of the populace apparently selected at random. When they die, Togomor should declare this a final gasp of the Urgathoan menace, a secret second stage of the plague which the first step of the cure was insufficient to resolve. This will be unprovable, but believable, and misdirect attention away from you. You may nevertheless face some difficulties, but your path will be easier.
You may also be wondering who I am. The answer should be evident, but not all are as clever as I. The first and clearest part of this is that I do, as you have seen, have access to prophecy. Its erasure was incomplete. To demonstrate this, first note this letter was sent to the Bank the day prior to the breaching festival. Nevertheless, I can tell you how it went. First was the master thief, whose cards allowed her to pick many of the locked doors. She failed at the Symbol of Death, which first destroyed her protective jewelry, then took her with its second pulse. Second was the barbarian. He smashed his way through the prismatic wall and the subsequent elementals, but then his fury was burnt out, and he could go no further. Third was the Academae professor. He breached his way to the Doors of Scouring, twice becoming as ice — at first for many doors, then again after it was dispelled by the Symbol upon the Door of Flame to negate the risks of the shadows. His only weapon against the Doors of Scouring, however, was a scroll of Disjunction. After seeing his performance, the other contestants admitted defeat, refusing to make their own attempts even after the doors recovered their magic.
So, who might have handled the fall of Aroden well? Think on what you know of my traits.
Once you put the pieces together, you will note this explains many things. My taste for information, connections, and properly swaying the public with the release of information is evident. My delight in operating undercover, without anyone's knowledge, and especially under the nose of a god like Abadar is well-known. And, of course, my enjoyment of a plan like this, especially with its true origins secret and ripe for blackmail, is clear. My agent in writing this letters would not acknowledge the truth of my claims, and in fact you will find them unprovable. I would not write this if anyone could prove it. As far as anyone knows, I will remain as I ever was, most certainly doing something suspicious, but not ever quite, provably, violating the laws of the divine. As law is nothing without crime, though, crime is no fun with nobody who could possibly spot it. The only price I ask of this part is that you demonstrate my cleverness, not on Golarion, but to other deities. You cannot prove my access to prophecy, but your evidence will ensure nothing gets too easy for the other three. They're getting a bit boring.
—You Already Know