Otherworld

"It was our greatest shame, and our most terrible tragedy. In that age, the Force was ours to wield. It came to our will as a birthright - as natural as the light of a sun bathed a world born into its light, so were we too born into its power. We knew it was our destiny to be bask in its brilliance, architects of its immense power. Perhaps it would have been, had we quelled our inquisitive minds and not beckoned to the hollowed one's call. How foolish we were! As arrogant children tampering with a force beyond our comprehension. But how could we have known? It is a dreaded truth to bear, the knowledge that it was through our actions we had condemned a galaxy. An extinction aeons in the making, from the damning of the shadows of a blackened world."

- Epizon, explaining the Kathol species' experimentation with the Void on the Otherworld

The Otherworld, originally known simply as the dark world, was a rogue planet that resided in a rift in space known as the Chasm, a tear between the realspace galaxy and the Otherspace galaxy which was inadvertently caused by the Kathol. In the era of the ancient galactic civilizations, the Kathol had frequently experimentation with dimensional manipulation though a superweapon known as the Metavasis, which ultimately shattered space between realspace and Otherspace, granting the Kathol access to a planet engulfed in lightless space, which they dubbed "the dark world".

Through the positioning of the dark world, which eventually was dubbed as the Otherworld, the Kathol were able to experiment with the properties and elements of Otherspace, such as the advantage of harnessing protomatter, the discovery of the Void and the Presence, and exploration of Otherspace itself. On the Otherworld, the Kathol established what was considered by them to be their greatest research facility, called the Menhir. Ultimately, the Kathol experiments exposed them, and the realspace galaxy, to the Presence and the Void, as they unintentionally created the first "breach" in the galaxy, a Void occlus.

Weakening the previously ubiquitous fabric of the Force by the creation of a "wound", the Kathol were considered to have been conclusively responsible for the inevitable Extant War, and the apparent attempted destruction of the Force by the Presence.