I could diplomacize, but I have no clue wtf is going on.government sanctioned mass murder.
More like liberating them from free will and the weaknesses of the flesh. The Magedom has a strong philosophy of " if you won't play alongside us while alive, then you will do so after being dead".
I don't even remember what we were supposed to be after/doing... Isn't there some artifact, that was stolen from the Magedom by the Order of Light, that we were supposed to steal/take? Do we know what this item is?
Yes. You even have a map pointing its location. It's still a bit away from this city.
Altough if you want to defect/convert with the magedom, that's up to you. Kristoff's too lazy for having planted sigil bombs in the back of your heads in case you tried to divert from his orders.