So what's the question? Why does Azalin send S. out on this grand trip? Why S. and not someone else? What does he need the bracers for? And how do the GCs children factor in? Also, why would the GC spawn all these children? Why these, and no others? And why all of them dispersed across the whole demiplane? Does Azalin know why the GC did this?
Well, I have just about no clue - but guessing is fun, so why not?
Guess 1: It doesn't seem likely that both the GC and Azalin share the same agenda for the children
Guess 2: There's some reason why they are so spread out. And Azalin seems to know pretty early on that S. will have to travel the entire demiplane in order to learn all he needs to know
Guess 3: The reason for them being so spread out might have to do with availability of fitting mating partners? hmm. Or because something might happen if they all came together? Or they need to be tailored to each domain somehow?
Guess 4: Well, if I understood and remember this right, the GC has some kind of reality wrinkle - and reality wrinkles have something to do with a connection to the land. The whole demiplane started with Strahd forging his connection to Barovia...
Guess 5: So maybe the GC is trying to do something else than all other fiends? Something at a much grander scale? I'd think that his offspring likely won't have a reality wrinkle themselves - but might the GC-part of their souls inherit something like both? The connection to the land that special natives of a particular domain share, as well as the reality-wrinkling essence of the fiend? Is the GC perhaps trying to connect to every-single domain in the demiplane by his blood? Some kind of greater blood ritual? Are the chilldren to be sacrificed in some way? Or does he want them to wrest control of domains from the DLs? The latter seems unlikely, though...
Guess 6: In RL, every single domain has it's own special essence, it's very special feeling to it, etc. Of course the DL plays a role, but there's always talk of the land.
Guess 7: Why a war throughout the western core? Why would other factions be un-affected? And if this is but a side effect? Well.. many of the children appear to be relatively "weak". It seems unlikely that they would all become darklords, or any such thing
Guess 8: Azalin seeks to learn about each of the children, but there's no mentioning of attempts to capture them, or move agianst them, or anything. Perhaps they still have to do something before he'd take any action. What could this be? Do the bracers have any connection to this? Do they help Azalin to identify or control any of the GC's offspring? Or do they let him participate in whatever effect their existance creates?
Guess 9: I'd imagine that whatever is going to happen with the children would create adventure opportunies for every single domain. E.g., maybe PCs could start anywhere, and become involved to something related to the particular GC-child in the area. I'd imagine that whatever that is, it would always have to do with altering the domain by the influence of the spawn. quite subtly at first, then maybe more strongly. So what would happen, if anyone killed any of the children? Would that disrupt the greater things at work? Likely not. In the grand conjunction, the PCs could be quite "successfull" all the time, and still the whole thing would move on. Also. I'd think that whatever the children are supposed to be doing would created a series of connected adventures spanning several levels. Maybe, as each of them performs some kind of vile act, something that would cause a very special tragedy in that domain, the threat caused by the remaining ones, the GC, and Azalin would increase? Starting to tear on the fabric of the demiplane, or something?
Is Azalin trying to destroy the dark powers? Or trying to use extortion against them?
...likely all wrong anyhow - but I'd think I could think of something fun if I was still running a campaign
