Hades

The Gray Wastes of Hades is the Neutral Evil plane in the Dungeons & Dragons great wheel cosmology.

Its favourable location of equal "subjective" distance between the Abyss and Hell make it the most active battle-zone in the Blood War, where Demons and Devils clash over who is the most evil. Unfortunately this distracts from what Hades is all about.

It is the inverse of Elysium, being the place of ultimate evil in the existence. Worse perhaps than the Abyss or Baator if only because it is not subject to the capricious whimsy of Chaos or the restrictions of Law. Therefore it is a bleak place of suffering and misery.

Layers

Like Elysium, Hades has an all pervading aura that causes visitors to be ensnared by its nature. In this case the removal of anything joyous or worthwhile.

By merely stepping onto the plane, non-evil individuals will be subjected to harsh penalties to their mental faculties, which makes colours appear duller and sounds seem more muted. Emotions seem more alien, and visitors find themselves less empathetic or caring than they used to be.

Not only that, but the plane is also home to a unique malady known as "The Grays", which affects all visitors, including evil ones and even if they are outsiders. This steadily causes those afflicted to lose their mental faculties for every day spent abroad in Hades as they become more detached from reality and hope. In rules terms this forces their wisdom score to drop for each failed attempt to resist the condition, bringing their ability to think ever downwards until they lose their sensibilities altogether and go mad. Of course this is more dangerous for non-evil people since their senses have already been assaulted by the bleak nature of the plane, meaning they are more likely to be overcome unless they have wills of steel. The only immunity is offered to those who have high enough levels of spell resistance. However the cure is simple: get them away from Hades and their madness clears itself naturally.

The last defence of the plane is its entrapping nature, with every week spent on the plane slowly bringing visitors down to its level. This is the plane exerting itself on the better natures of non-outsiders such as demons and devils. Making them forget the happy memories, or distorting their feelings into something twisted and spiteful. This of course is coupled with the influence the plane has on the sense, and the affliction of the Grays, meaning the minds of people who come here will eventually crack. Eventually they forget what it means to have hope and joy and they become trapped in the plane, unwilling to leave and are more likely to descend further into madness if the Grays has not gripped them already.