Subspace

If Death's Shroud is the physical manifestation of space, then Subspace is its ethereal twin. Subspace exists within and without the physical structure of the universe, and is just as spread out throughout the universe as Death's Shroud. Normally untraversable and invisible to the naked eye, Subspace can be accessed and even manipulated by certain means and individuals.

Physical Nature
Subspace is the runoff of the Great Light that has been choked and filtered through Death's Shroud. As such it is far less deadly to complex life forms and their creations than the Great Light itself is, but vast areas can still outright Obliterate the average Being on contact.

The Astral Plane and the Precipice
Located in the Triad and across its immediate neighbors.

The Astral Plane is a developed region of Subspace that powerful Beings can survive in and, on occasion, make use of. It is a creation of Tau Sunflare and she is responsible for keeping it stable. It takes the form of a extremely large open area only slightly smaller than the empty space surrounding the Triad itself. The "surface" of this place is constantly shifting, and only those with considerable power can manipulate it to keep their footing. The entire world is extremely colourful and bright, with streams of controlled energy crossing through the "sky".

The Precipice World, also known as the Dangai, is the Astral Plane's dark counterpart. It was put together by the Soul King. The Precipice World takes the form of seemingly endless tunnels that connect the worlds of the Triad to each other and others past their pocket of space. Rather than selectively condensing the energy of Subspace into deadly streams like in the Astral Plane, in the Precipice World those streams are the only foothold available, and the chaotic energy is barely held back in the walls of the tunnels. Because of this set up even powerless Beings can travel through the Precipice without harm, so long as they don't touch the walls...