Board Thread:Lore Discussion/@comment-6702118-20140722142914/@comment-32671129-20180722095430

Alduin is an aspect of Akatosh. wrong  Alduin is an aspect of Aka

Deadra are not aspects of the gods-they are gods. Deadra and Aedra are all et'Ada. The difference is that Aedra create Mundus and lose great part of their power while Deadra did not. So Deadra > Aedra

Also Alduin can probably best any Deadra on Mundus but not on Oblivion.