The Book of Daedra mentions that Hermaeus Mora's sphere is the divining of fate, explictly mentioning reading the future in the stars, which are connected to Magnus. The Imperial Census of Daedra (http://imperial-library.info/content/imperial-census-daedra-lords) mentions how he claims to be born of thrown away ideas for the creation of Mundus. In Nordic mythology he is a woodland demon, while if you believe in the theory that Magnus=Dagon, Magnus was formerly a Leaper Demon in Nordic myths. And everyone knows that magic and knowledge are traditionally linked. What I am saying is that Hermaeus Mora is formed of the potential earthbones that would've been part of Nirn if Magnus stayed instead of retreating to Aetherius. As such, he is naturally connected to Magnus. No wonder why he is so alien in appearance: he is not merely a deity of knowledge, he is a personification of lost laws of physics.