The Shackled City
Plain of Cysts
The Plain of Cysts is the site of an ancient battle fought between the denizens of Occipitus and the angelic host. The massive ovoid cysts were formed around the bodies of celestials and any good-aligned magical equipment left on the field of battle because the plane had a much harder time absorbing them. This is one of the areas on Occipitus that demons consider to be the most haunted and unlucky for their kind. The lore states that the more of these celestials that get successfully absorbed by the layer, the further removed it is from the Abyss.
In order to pass the Test of Resolve, the adventurers had to follow a path selected by Adimarchus which was revealed by the lantern of guidance. Every time they strayed from the path by failing to make forward progress, anything within twenty feet of the lantern was teleported back to the ridge west of the Plain of Cysts. Perseverance paid off, and despite the loss of Elias Hoog to assassins, the adventurers made it to the end, which proved to be a teleportation circle that sent them to the other side of Occipitus.