The Void

The Void, Birthplace of Originators
True nature of The Void cannot be comprehended with human senses. It's a place outside the universe, parallel to The Reality separating physical world of matter and eternal world of dreams, not fully physical nor eteric. Those who dared to enter there described it as "endless cave at the bottom of infinitely deep sea". Time doesn't exist in The Void so this entire place is still forever and those who enter won't age and will never feel hunger, thirst or cold.

History
Before there was time, before there was matter and The Reality there were dreams. Realm of bliss and creation that was, is and will ever be. Old Dreamers created concepts and feelings within their dreams, until one of Dreamers later named The First Being wanted their dreams to be real. The matter they created and space they digged are known since then as The Reality but the space around it was left unfinished and empty, becoming their dark sarcophagus. Out of their will The Originators came to be with the purpose to fill the universe with creation and life, and so they do to this very day.

Space around the universe was left untouched by them but as the lifeforms they made advanced and evolved, at some points even race so primitive as humans were able to discover it, feel it, try and fail to understand it, even give it a name - The Void.

And also find horrific use for it. Humans made The Void a prison. Eternal ones they found dangerous or uncooperative were thrown into this darkness, some lost forever and some rescued. Trapping anyone there was however later declared inhumane and since then opening Void Portals was banned forever.

Trivia

 * The Void was first shown in 1.3 update for Deep in Dungeon, as optional 6th chapter. It features no chests, shop and, unlike any other floor in Ooran Dungeon - no enemies, expect nameless boss. The player (Cane or Eleya) entering through the portal is not canon.
 * For a mortal or eternal one it's impossible to die while in The Void.
 * Many demons trapped there during Age of Conquer came back, usually with deep psychological trauma. Examples being The Maze Master or The Warper.
 * It is possible for creatures trapped in The Void to find each other, although it's very unlikely considering that The Void is nearly infinite.