According to Olihoot, the planes and realms are divided into "layers." The best description of how this works is to compare it to a canvas with the painting of a port-city. There are four major parts involved in this. The Aether, which is also known as Souleria, and represented by the painted sky. On the opposite side of the Aether is the Nether, which is represented by the ocean. In the center, the city itself represents the Ether, which is most-commonly referred to as the Void. The fourth and final major part of the theory is the Xether, which is represented by the canvas on-which the painting has been made.
The Void is the place in which all mortal and elemental realms are placed. They themselves are also separated into layers and positioned to encircle a central section. Although the Void expands infinitely outwards, Oblivion is at its center; described as a swirling black hole. While most realms are separated from the Void by way of an Outland, the Outland of Oblivion is better known as the Abyss and is the only section in which mortals may roam, however ill-advised this is.
While the planes of Souleria and the Nether are primarily devoid of realms in their own right, the immense realms of Zenith and Anserak encroach into them. Returning to the painting analogy, the clouds can be described to represent Zenith while the city's reflection in the water can be described as Anserak. These two realms were created by Olihoot to serve special purpose. Running through the dimension's core is a "well" of infinite power. One side of the well is known as the "Well of Sins," while the other side carries the title "Well of Souls." Responsible for safely drawing the energies of the Nether and Aether into the Void, the Twin Wells are said to be responsible for all life. They are housed, respectively, by the forged realms of Anserak and Zenith.
Anserak's Well of Sins strips the negative energies from souls and pulls them downward into the Nether, from where they came. Zenith's Well of Souls strips the unique energy of a soul and pulls them upward into the Aether, from where they came. Prior to the intervention of a legendary band of heroes, the Twin Wells served another purpose. Where the Well of Souls serves as a facet for reincarnation, so too did the Twin Wells serve as a seed for the reincarnation of the Void. This was carried out every eon through an Unseen Artifact known as the Eternity Cube.
Its destruction caused corruption in the Aether and Nether, also leading to heavy damage to the Twin Wells, Anserak, and Zenith. The damage to Anserak caused its collected negative energies to begin bleeding into the fine, hidden layer which separates the Nether, Ether, and Aether from the Xether. This plane is known as Az-Ezal, the "Plane of Not." Here were born the parasitic Nytcophae, also known as "Nightmares." Damage to Zenith caused the energy of souls to bleed into the Ether, resulting in the incredibly dangerous anamoly referred to as "The Brood."
This section serves as a portal-nexus for information on the various realms and planes, themselves.
Dark Eden (Delym'Neminur)
Solas Gealai, Realm of the Moonlight
Solas Realta, Realm of the Starlight
The Void (Ether)