okay, wait. so as much as john says that the Dark World isn't designed for any particular purpose, we see that there are places that are thematically designed for the hunter in the area. The rat catcher has so many rats to catch(which, aaugh!!! Is that a reference to spys/rats, or a reference to like racism being like this person is a rat mascaurading as a human? Questions, questions...), frederick was a soldier, and therefore his domain was centered around killing other people in war. It even played into John's [fears? Wants? Worse self?] , from what little we've heard, a cathedral of bones plays well into the "power-hungry king" thing.
From what we've seen so far, people's domains seem to be these mass graves, where those without a domain of their own fall to those with?
This kinda leaves more questions like what seperates the domain-holders(the ratcatcher and frederick don't seem to *want* to leave) from those who aren't bound to these domains (frederick mentioned people fleeing from the disease past the field) ? Is it force of motive? From what we've seen with Frederick it seems he didn't know that he was dead (i.e "I never left the war, did i?" I think. Dont remember the exact quote). So, then, the real question was whether the domain *was already there*, or it was *caused by Frederick*.