oh, well that svcks. can they you know, like, manifest? do they have personalities?
Yes, they have on occasion, namely as avatars. We see a few during the course of Morrowind, and a avatar of Akatosh at the end of Oblivion.
Mind to OP, that these "avatars" are probably just reflections of mortal belief, as all things Aedra tend to be. That is to say, the Aedra are dead, so they obviously aren't alive. Mortal belief bends their corpses (or rather, refracts light through their corpses that are lenses) to become different personalities; this is why Alduin, Akatosh, Alessian-Akatosh, Alkosh, Tosh Raka, and Alduin are all different gods (Alessia-Akatosh and Tosh Raka may be exceptions to this rule, but probably aren't), as the same with Kyne and Kynereth, etc.
Daedra have a more "solid" existence in regards to their personality and manifestations, because they aren't dead.
Aedra are dead, chopped up, pieces of god-flesh grafted together into an abominable universe. And no, they do not live in a dope ass palace. I smell a meme coming on.
A final note, Aedra's souls (or maybe pieces of them) exist in Aetherius. Maybe. Very unlikely, but not outside of the realm of possibility.
Alright, scratch that, there is the tribunal. But they were using the heart of Lorkhan.
They didn't mantle. Well, Vivec maybe, but he mantled himself if he did from another timestream.
Mantling doesn't work that way either. Mantling is when something and something else become so alike no one can tell the difference which means there is no difference. See Sheogorath/Champion of Cyrodiil and Hjalti+Ysmir+Artcus/Tiber Septim/Lorkhan/Shor/Talos.