Also known as: the Nether
The Twisting Nether is the astral plane between worlds. It is a chaotic and magical environment that overlaps with the Great Dark Beyond, yet is normally imperceptible to mortals.
There are a thousand ways to perceive the Nether, every voyager sees it differently, depending on circumstance, form, and state of mind. Illidan projecting his spirit into the Nether saw it as a black, airless void in which a billion stars twinkled, and behind and beneath him blazed the world from which he had come. A snake of energy leading out into infinity represented the flow of energy of the portals the Burning Legion use. Turalyon perceived it as a chaotic realm where the universes sparked by the Light and Shadow bled together; a place of pitch black skies, twisting and filled with strange, conflicting powers. Countless worlds appear on the edge, seemingly close enough to touch and yet unimaginably far away. The Light intermingles with the Shadow, the primal uncontrolled forces of chaos and order, life and death, clash.
The Nether, though separate from the physical universe, still has physical objects, such as planets. It transcends all realities and is normally imperceptible to mortals. Time passes differently deep inside the Twisting Nether, and it is impossible to tell whether days, years, or centuries have passed. Turalyon and Alleria have fought in the Nether for a thousand years from their perspective, while on Azeroth it has been only a few decades. A week on Azeroth could be a month in the Nether, or ten or many, many more.
From within the Nether, Turalyon could witness Draenor's destruction without being there. He was standing in Hellfire Peninsula, in a copy, or illusion, of Draenor, witnessing the cataclysm all around him, and yet unaffected by any of it, until Lothraxion extirped him from the Twisting Nether and brought him back to the real Draenor, now Outland.
Before life began and before even the universe existed, there was only the Light. The Light existed as a boundless sea of living energy, swelling across all of existence, unfettered by time and space. Yet as the ever-shifting sea expanded, pockets of cold nothingness appeared. From these, the Void was born. The Void quickly grew and began to move against the Light. Eventually, the mounting tension between the two forces ignited a series of explosions that ruptured the very fabric of creation, giving birth to the physical universe.
The energies released from the clash between Light and Void raged across the nascent universe, forming countless primordial worlds. For long epochs, the ever-expanding Great Dark Beyond broiled in a maelstrom of fire and magic. Shards of Light were flung throughout reality, suffusing worlds with the spark of life.
The most unstable energies however coalesced into an astral dimension now known as the Twisting Nether. Light and Void collided and bled together at the edges of this realm, throwing it into turmoil. Their energies would give birth to the very first demons. The Twisting Nether is the only place where demons can truly die. Although the Twisting Nether existed outside the borders of the physical universe, its volatile energies would occasionally tear through the veil of the Great Dark, flooding into reality and warping creation.