K, so some two cents to add to this:
Nirn is, in a way, Lorkhan's plane of Oblivion:Evidence:
- Lorkhan is Padomic. Other Padomics create static realms around themselves, while other Aedra traditionally moved from world to world, and would've continued to do so without him.
- Adding to Lorkhan's self in a way, and being absorbed partially into him, would better explain his act of trickery. Rather than a design flaw that Magnus had overlooked, Lorkhan took the designs into himself before directing all the Aedra in, rather than creating an plane independent of himself. Hence why Magnus didn't forsee this.
- It was already introduced into the canon as a belief (a Mythic Dawn belief that may not be baseless).
- Becoming a concrete part of another deity's daedric realm would presumably be a way to drain divinity from them for the realm's own purposes.
- Despite having his heart torn out, his body cut into several pieces (moons+Nirn?), etc, Lorkhan's influence persists in Nirn. The Aedra could not destroy his heart, e has had avatars that did stuff for the Nords, etc. despite his death. Meanwhile, other aedra in Nirn have died and stayed dead (i.e. the planets).
Now, under this interpretation, Nirn wouldn't be a
real realm of Oblivion, because of the aedra's influence, being absorbed into it, and being part of it beyond Lorkhan's control. Basically, their collective control matched his own, creating something of an independent realm, and the aedra that stayed and retained influence, tried to make the best of their limited control, to try for the world they had intended to design.
Another concequence of this would be that the Nords, may essentially be Lorkhan's lesser daedra:
- They claim they were created on The Throat of the World, rather than being descentants of the first people. Under this interpretation, this would be correct. Some Nords then ended up on Atmora, and founded their own pure-nordic community, while the rest wandered, and interbred with the wandering first peoples, creating them other races of men, which entered into conflict with the mer.
- It is also a Nordic claim that they originally had exceedingly long lives, but Alduin/Akatosh robbed them of their years. This may concide with Lorkhan, who they would essentially be part of, being torn assunder.
Just an idea, and one that could be developed further, but I'm liking it so far.
Also, not so sure about the interpretation of Alduin be "hungry" per se, I'd say it's more wanting to move/lead on, now that he was no longer bound to an agreement. The god of time and world creator/destroyer aspects of him come from him leading the aedra from one world to the next, indicating when it is time to go. ...If he wants to rip Nirn in two by pulling all of the Aedra/aedra-derived beings from it. well, it would be bad for anything that wanted to stay. I could also see the "brothers" of the Nords, Imperials or Bretons, fighting them, as they have a different heritage, and may be able to have a divine connection returned to them by abandoning Nirn, hence a civil war.