The Abyss

A shard of evil, born from the antithesis of creation, chaos incarnate bores its way through space as if magnetically opposed to the purity is so despises. It sarves downward into infinitum the abyss, the domain under which all evil continues to engorge itself on chaos and darkness. But does the abyss attract that which is evil, or does it mold one's madness into the very likeness of itself? Of only one thing I am certain: The chaos is its own undoing and the sole reason it has not engulfed the entirety of creation thus far.

— Origin Mythos

The Abyss was first documented in modernity by Prudeflyn in The Catalog of Planes, but ancient accounts and legends exist of the abyss, often tied to apocalyptic prophecies.

The Abyss is the domain of demons, forever at war both within and without. The plane is a bottomless pit, with regions roughly divided along the vertical of the pit into layers and princedoms. Only the upper layers of the abyss seem to have a plethora of portals elsewhere, the deeper you go the rarer they seem to become. Each layer has a massive hole in the center where one can ascen and descend layers. Layers can be massive, many times the landmass of Estia and contain entire oceans and continents within themselves. There is no single ruler of the abyss, rather regions of a layer, an entire layer or multiple layers are ruled by Lords or Princes. The layers of the abyss are beyond trecherous, not only are the inhabitants strong, deadly and have a bent towards chaotic destruction but the plane itself seems to have a deadling, maddening and oppressive nature.

— Catalog of Planes

Other documented accounts come indirectly through encounters with the inhabitants of the abyss, primarily demons, and the cults who worship entities that are presumed to be abyssal. Various cultures and cults describe demonic overlords, princes of darkness and deep abominations all originating from some form of the abyss. A well known elven scholar, Edrym Torhana set out on a mission to map the abyss based on the various accounts from myths and cults, but disappeared after 10 years of work. The state of his study after his disappearance led many to believe he'd gone mad at the task and they locked up his research to prevent others from suffering the same fate.