Leareth,
This letter was written with Vanyel's assistance, but I, Iomedae, Knight-Commander of the Knights of Ozem, am the primary author. I arrived in K'Treva Vale shortly before the explosion, and I think it may have been a response to me, though I don't know how or why. I think that I am from another world.
I think that the existence of, and possibility of contact with, my world may change the justification for your war. I hope that this is so.
I think that it will be much costlier for you to go to war with Valdemar while I am inclined to defend them against conquest. I am so inclined. You could persuade me either that this defense is entirely futile or that your war is justified, though only with great difficulty. I will almost certainly defend Valdemar if you attack at present. My presence on a battlefield is usually decisive.
Vanyel has explained your grievances with the local gods and some, to me, seem legitimate. In the interests of honesty I must disclose that I am a selected follower of the god Aroden in my own world, part of an institution by which the gods select specific people who are then highly trusted and highly reliable, and given positions of authority accordingly. This system is like the heralds in some respects, but were Aroden to renounce me I would be only an ordinary amount of grieved by this, I can renounce Him if I cease to believe that serving Him is the best path for me to achieve the goals I believe I share with Him, and I can fight the gods if it seems like a good idea (which it does, for some gods and some fights). The grievances about the conduct of the gods that were explained to me do not seem to be to be applicable to Aroden.
Aroden was a human once, and he represents that ascension did not change what he strived for, or his commitment to dealing rightly by others.
Aroden ascended without killing other people, by a mechanism called the Starstone that remains in our world and still functions. Others have used it to ascend after Him.
Aroden cannot operate in this world at this time. I will likely take steps to change that. You could ask me not to do that, if it seems to you that it might have greatly negative effects.
In my world, the dead are sorted according to their character and then go to the Outer Planes, where they can live forever. Many of the Outer Planes including Aroden's are paradises. (Some are not. We are working on fixing that.) I am grieved to learn that this is not so in your world, and would be willing to work with you on finding a way to fix that, though not through conquest and mass human sacrifice. Introducing Aroden on this world might do it.
I have no desire for war. It is among the most tragic of human endeavors. I have been at war for nearly all my life and am very good at it. I am immune to compulsions. I am immune to fear. I have other forms of protection against magical attack which I do not expect at this time it's a good idea to specify. I do not know of a good basis for comparison across worlds, but in my own world the only powers that could survive in my presence on the battlefield for six seconds are halfway to being gods.
I survived the K'Treva Vale explosion and believe that I would survive a Final Strike for the same reason. If you wish to test this I request that you notify me in advance so I can go somewhere where your attempt will not cause civilian casualties. I will take no precautions against assassination on receiving such notice that I wasn't taking already, except for avoiding civilians.
The communications in this message are intended as part of a peace negotiation. Were we negotiating by the norms of the world I am from, that would have the following implications: I will, to the best of my abilities, not position myself to make inferences about your capabilities from the timing and process for the exchange of letters, and not use the contents against the aims of the peace process. I will not harm your agents in the course of their operations related to these negotiations. If you provide information or resources conditional on my agreement to terms I do not agree to, I will send them back. I will not lie. I will attest to the contents of this letter under truth magic, as relevant; I will swear not only that this communication is true to the best of my knowledge, but that the best of my knowledge is very good; that when I make claims in contexts like this one I am usually correct.
If you were to, for example, take this peace communication as a prompt to attempt to kidnap me, before knowledge of me would otherwise have reached you, this would be, in the terms familiar in my world, indicative that this kind of mutually cooperative and Lawful interaction will not work. I mostly expect that, regardless of your intent, this negotiation will not proceed along the terms familiar for Lawful negotiation in my own world, because we are alien to each other, and nearly certain to face much mutual incomprehension. But I am trying to make this negotiation possible for you and advantageous for you, and will do so past the first several points where it seems to me you are not doing the same.
With regards,
Iomedae, Knight-Commander of the Knights of Ozem and of the Shining Crusade