Malfeas is the mad Shenti realm of the Wyrm located in the Deep Umbra. This is a hellish nightmare world full of every horrible thing imaginable, and a few things so horrible that simply trying to imagine them would drive people insane.
Malfeas is ruled by the Maeljin Incarna, 13 great Banes that fight each other as often as they try to destroy the Garou. Their various territories within Malfeas reflect their associations. Lady Aife, the Caliph of Pain, has a domain filled with all manner of agony-inducing torments to break the bodies of visitors, while the domain of Doge Klypse, the Archbishop of Madness, is full of things that break minds.
The most well known area in Malfeas is the Black Spiral Labyrinth. It's a mind-bending structure that defies several laws of physics and drives anyone that tries to navigate it insane and into the arms of the Wyrm. Black Spiral Dancers take their name from the Labyrinth and often try to prove their devotion to the Wyrm by dancing ever deeper into the labyrinth, searching for revelations, but usually only driving themselves ever more mad.