Where do the et'Ada regenerate from after bodily destruction?

So there seems to be some uncertainty here.

On the USEP we can find the following explanation:

We do not die. We do not fear death. Destroy the Body, and the Animus is cast into The Darkness. But the Animus returns.

Now according the USEP "The Darkness" refers to the nothingness outside the Aurbis (ie Sithis), which I find strange as I was under the impression that the Daedra reform in Oblivion.

And what about the Magna Ge? They probably reform in Aetherius right?

Try to include your sources with your answers if you can.