Aetherius

Aetherius is the realm from which Aedra such as the Eight Divines originate. It can be compared to the Void, from which the planes of Oblivion and the Daedra within them exist. The Void, and by extension Oblivion, are therefore considered the dualistic inverse of Aetherius. Some have even gone as far as to call it the "Un-Void".

It is the plane of pure magicka, and it's the realm where magicka was said to originate. Common belief is that souls ascend to this location upon death. The Imperial Geographic Society have this to say about it:

"It is aetherial energy that infuses our daily existence, from highest to lowest, and gives all the races of men, mer, and beast common purpose. Its magic brings the rain to the fields, love to our hearths, and scientific principles to our technological industries. It gives us the very Sun itself. Finally, Aetherius is the home to the Aedra, those cornerstones of the Mundus whose aspects we see in the temple, in lordship, and the high walk of heroes."

Areas within Aetherius

 * Sovngarde
 * Mantellan Crux - a self-contained prison for the Mantella.

Reaching Aetherius
It is substantially more difficult to reach Aetherius than it is to reach the Void of Oblivion. The only two successful trips there occurred firstly during the Reman Dynasty, and secondly by the "Sun Birds" of Alinor. From the Reman Dynasty, the Royal Imperial "Mannanauts" were obtained, and from the Sun Birds, the Orrery of Firsthold. It is also rumored that the Dwemer may have reached Aetherius in the past, as well. It is also rumored that the stars are direct portals to Aetherius and that they were created when holes were blasted through Aetherius during the creation of Nirn. Also, the Dragonborn reached Sovngarde, a realm of Aetherius, in the main quest of.

Daggerfall
The Hero of Daggerfall entered Aetherius' sub-realm Mantellan Crux to extract the Mantella for use against the Underking. The realm exists as a massive labyrinthine puzzle. Sheogorath is encountered here, in his parlor. Although, in later titles, Sheogorath become associated with the realm of Oblivion, Aetherius' converse, he was not included as such in Daggerfall.

Oblivion
In, Aetherius is mentioned in passing in the form of a Heaven Stone named Aetherius Stone. It is located northwest of Skingrad and slightly south of Bleak Flats Cave. Activating it Fortifies Magicka 50 pts and adds Resist Magic 20%.

Skyrim
The priestess at Helgen commends the Dragonborn's soul to Aetherius, regardless of races.

When seeking entry for the first time to the College of Winterhold, the conversation with the watcher of the bridge may turn so that this response may be given : "I want to unravel the mysteries of Aetherius," to which she responds with acknowledgement that it is a noble goal to wish to understand the plane from which all magic comes from.

Dawnguard
Aetherium is a rare, luminescent blue crystal found in Dwemer ruins. While it has a strong magical aura, it is alchemically inert, and no known process can enchant, smelt, mold, bind, or break it. It is later discovered during Lost to the Ages that the ancient Dwemer Aetherium Forge is the only know forge that can be used to craft the material.

Quests

 * Journey to Aetherius -
 * Sovngarde (Quest) -