Limbo

Limbo is a realm on the edge of the Brass Realms, also called the "end of the world". Here, in this place most removed from law, reality unravels and only entropy remains.
It is a land composed of lifeless grey dunes as far as the eye reaches, with a sense of silent despair and hopelessness ever-present.

Limbo touches both the Spirit World as well as the material world. It carries aspects of both, it is only half-real, much of it can be influenced by the perceptions of any travelers.

Limbo is the main battleground where the Mechanoids defend the Brass Realms. Outsiders roam the desert dunes, and woe be upon any travelers that come across them.

Reality and Possibility

Within Limbo reality unravels. The plane is so saturated with the clashing energies of order and chaos that any material certainty falls apart into a myriad of possibility, until everything loses all substance and vanishes into dust and sound and eventually silence.

Echoes of the past: Creatures that enter Limbo and spend time there start to have memories of pivotal moments in their past and the choices they made at those times. They are filled with a melancholy mood and start to imagine ways their life could have gone, what could have been.
Echoes of Possibility: Eventually, creatures and objects that find themselves in Limbo slowly start to 'blur' and gain ethereal outlines and 'echoes' of different possible versions of themselves, of things that could have been but aren't. A warrior might produce echoes such as a maimed beggar, a knight, a baron, a farmer. All possible ways that man's life could have gone, some more likely, some less.
Vanishing into nothing: As the echoes of a person or object become more distinct, the original 'true' subject becomes less substantial in turn. Eventually the echoes separate fully, leaving the original lesser in complexity and substance, themselves turning into mere possibility, a mere echo. Detached echoes of people wander Limbo, talking to unseen companions as if they were on their own journey. These echoes also eventually fracture further into lesser and lesser echoes, more and more insubstantial with every iteration. Eventually, they come apart into nothing but a handful of dust.

Oceans of Chaos

Spread throughout the dunes of Limbo are prismatic flat oceans, lakes and even the occasional puddle. However at the bottom of these bodies of water are portals to the Outside. From these oceans and lakes come crawling the Outsiders; beings that are anathema to the order of the Brass Realms.

The Oblivion war

Surrounding the Oceans of Chaos are outposts and fortresses of metal, built by the Mechanoids. Here armies of automatons are stationed at all times, ready to defeat incursions and enforce the borders of reality. The war is constant and never-ending; while there may be decades or centuries of no significant activity, the norm is endless hordes of chaotic horrors throwing themselves at the metal bastions trying to invade the realms.
The war can never end, for if the Mechanoids ever fail in their constant vigil the universe is surely doomed.
However, many smaller pools are left unguarded and stragglers and survivors occasionally escape the arm of law and wander the dunes. They roam the grey realm until they are eigther caught by a mechanoid patrol or until they figure out a way to escape into the wider realms.

Types:
Dead world
Flat World

Location:
The Border
The spirit world (?)

Realm Cloud Description:
Limbo's Planar clouds look like blotches of a a dull, muted grey.

Type

Dimensional plane