B
Oh boy. Brain control book. Time to start thinking about what we want and who we sacrifice. I'm thinking it should be the wife who goes. We are still young, and our only child is female, so if we widow ourselves quietly we likely have the opportunity to take on another beneficial political marriage.
As for what we want, lots of people are stating that we should use the boon to punish the Pantheonists. I'd say the best way to do this is to grant our army a boon (a long term improvement) and send them to purge the Pantheonists, rather than just siccing the demon directly on our enemies (a one time deal). The quickest way to improve our army quickly would be to take the Martial trait for ourselves, and Bjern is young enough that any trait we get from him could last us awhile. We know the demon can grant multiple traits in one go, so we might as well take healthy to try and extend the life of our demonicly buffed super-emperor.
We know that the demon can target our either our bloodline or the resident of our home when he comes back to collect payment. I wonder if we could structure the contract so that it specifically targets the residents of Methe rather than our descendants, thus allowing us to make the payment somebody else's problem by moving the capital.
Lastly, we know the ritual can backfire. Ideally we should set it up somewhere far from home so that there is no collateral damage should the worst happen. We could leave on a "romantic trip" with only our wife and most loyal Shadow Rank peeps, conduct the ritual away from prying eyes, and return without her claiming a tragic accident. This way our people will be neither aware of our actions nor put in danger by them.