The Pryson

An evil devouring reality which seeks out and hunts down evil beings and the dimensions they reside within.

A reality which exists by devouring and absorbing other realities.
While not intelligent by any measurable means, the reality hungers for great evils and those realities which host worlds steeped in evil tend to draw its interested.
No one knows how long the Pryson has existed. The number of realities it has devoured is near infinite.
When a reality is devoured, the evil within it is preserved and allowed to flourish within the confines of the Pryson. All who live within the Pryson are somewhat cursed with a true death rarely coming. When one dies, they are reborn, sometimes in the same framework or twisted version of reality of which tye died, sometimes in a brand new reality.
Time is also not fluid or linear within the Pryson, effects can precede cause. For lesser beings, their existence can be overwritten continually. While they may experience previous existences in the forms of dreams, for them, they remember little. For others of more a powerful nature, they may retain memories of alternate timelines. Some gain enough power to even be immune to changes in time, blithely going along with whatever the current situation is.

Within the entire framework of the Pryson, a political structure of government does exist, with those at the top known as the great Court. Membership of the great Court is constantly changing, with new lords arriving and old lords disappearing back into the mists of the Pryson almost daily. The Court's main goal is preserving the status quo, a semblance of normalcy at the center of the Pryson. They make sure that their lands are minimally invaded by the horrors which exist in the Pryson. Often times, the lords are the very evils, or somehow represent such evils, which drew the Pryson to their reality in the first place. An armed military exists in service to the Court, known as the Wardens.
Once something is part of the Pryson, it can never leave. Or almost never. Once in a great while, holes will appear in the intradimensional nature of the Pryson to the outside. When this happens, it is known as a Pryson breach. During these events, the evils of the Pryson slowly start to leak out into other worlds. Again, while the Pryson doesn't have an intelligence, it does act as an organism in that it reacts as if wounded and attempts to clot the wound.
Due to the disruption, the Court itself gets involved and attempts to seal the breach. Countless Wardens roam the outskirts of the Pryson, given considerable power by the Pryson itself, which they use to seal the breaches when they find them. Once done, a watchtower is created at the location of the breach, ensuring that nothing else escapes.
Wardens involved in the process of retrieving escaped evils have garnered the ability to leave the Pryson for brief periods of time. Within them, they hold the power of the Pryson and the ability to draw the evils they find back into the Pryson. Once all the escaped evils have returned, the Wardens themselves are called back. Despite the evil nature upon which the Pryson feeds and the overwhelming selfish nature of the lords of the Court, most of the Wardens are good and honorable, taking their duties seriously. To a Warden, the Pryson comes first and they see the Pryson as a just and needed balance to the Cosmos.