The Elemental Chaos

The Elemental Chaos is a plane of existence within the Great Prism cosmology. As the name implies, the Elemental Chaos is a roiling, tempestuous plane of raw elemental power, unburdened by the physics of the Prime Material Plane and where the core elements of fire, water, earth and air rule with equal ferocity.

Characteristics

Unlike other planes within the Great Prism, which can theoretically be "safely" visited by non-native outsiders (local hazards notwithstanding), the Elemental Chaos is completely uninhabitable to any creature not native to the plane itself. This is because, unlike other planes of existence, the Elemental Chaos is not a "world" but rather a dimension-sized swirling mass of elemental energy in its rawest state; nearly any creature that sets foot within this plane without proper preparation will be undoubtedly and almost instantly ripped to shreds by the raw power and intensity of this plane-spanning elemental storm.
Because of the nature of the Elemental Chaos, Convergence Zones between this plane and the Prime Material Plane are often the origin points of enormous natural disasters: a sufficiently large portal to the plane may unleash enough elemental energy to cause a massive hurricane, a tumultuous landslide, a large-scale flood, or a forest-devouring inferno. On a smaller scale, harnessing the power of the Elemental Chaos in a more controlled manner can prove to have practical applications: for example, a wizard specializing in conjuration might cast the fireball spell by briefly opening a portal to the Elemental Chaos near the intended target. Most commonly, the Elemental Chaos is accessed by practitioners of magic to perform the summoning of elementals (see below).

Inhabitants

While the Elemental Chaos is the home plane of the elementals, these creatures do not "live" within the plane in the conventional understanding of the word: within the Elemental Chaos, each of the four elements exists as a single hive-minded consciousness with limited intelligence; when an elemental is summoned to another plane, a "piece" of this consciousness is broken off and becomes its own separate entity. When an elemental is killed on another plane, its essence returns to the Elemental Chaos and is re-absorbed into the consciousness of its ruling element.
The way an elemental responds to its newfound independence can vary on a case-by-case basis: most elementals possess only a bestial level of intelligence, and most deeply resent and are pained by their separation from their greater elemental consciousness. As a result, an elemental that manages to break the control of its summoner becomes a self-destructive berserker, lashing out at any other living creatures in order to provoke them to destroy it so that it may return to its native plane. It is for this reason that summoning an elemental is considered a highly dangerous act for the untrained, and why maintaining concentration and control over a summoned elemental is of the utmost importance to any would-be conjurer.
In rarer cases, a sufficiently powerful elemental may develop its own independent level of sentience; this leads to the creation of powerful and intelligent elementals such as genies. For these elementals, sacrificing their individuality to return to the Elemental Chaos may be less of a priority, and some might outright refuse to return altogether. Ironically, intelligent elementals may become even more dangerous than mindless ones, as their awareness of their own mortality and desire to continue their independent existence makes them both more cunning as well as more desperate.

Type

Dimensional plane