The Duskfall is a small demiplane that overlaps the area where the city of Cathorn once stood. It resembles a dark reflection of Brightshore and the surrounding ruins. It is inhabited by undead, spirits, and even stranger creatures.
Adventurers have recently learned that the Duskfall was created at the height of Cathorn's power as a way to banish and imprison the forces of darkness. It seems that the towers of Cathorn (of which Kintsugi Tower was one) were the keys to maintaining the prison.
Among the creatures imprisoned there, perhaps the most powerful was Lilura Nuthixa. She was destroyed in 25 BY, in the same event that led to the ruins of Kintsugi Tower being replaced by the Duskfall's darker version, which is now known in Brightshore as Zren Tower.
In the basement of Zren Tower is a mirror that acts as a portal between Brightshore and the Duskfall.