Late to this post, but what the hell. Spoiler THEORY only based off Lore read in game.
Aurbis unless I got the name wrong, if so I'll simply use its terminology, the Void. It is considered "where" for lack of better word where Anu and Padomay exist. Anu at least to some stories had no will. Some said Padomay did as it was the ever changing to Anu's never changing. During their war their "blood" formed the Aedra and Daedra. However they stand different than the gods (both groups) as Anu and Padomay were infinite. The et'Ada weren't, they had limits on how much they could give into Nirn's creation.
While the Aedra formed worlds outward themselves. The Daedra formed worlds within themselves. So when a Daedra is destroyed, it's spiritual essence is sent back to its world. Alduin is powerful maybe even surpassing the Daedra. However according Paarthurnax, dragons being linked to time, still can't see past the end of time. So I think even if Alduin could destroy all the worlds including Aetherious, Oblivion, etc as Anu and Padomay are infinite they simply result a new world.
Anu and Padomay are Order and Madness. Peace and Mayhem. Pleasure and Pain. Love and hate. Hope and Despair. Light and Darkness. Both are neutral forces, that if one were to truly die I think reality would end truly. So I think Anu and Padomay surpass him.