From PathfinderWiki

Xovaikain is the home of Zon-Kuthon in the depth of the Netherworld. Formed by the Midnight Lord during his time in exile, Xovaikain is a lightless steel labyrinth of hopelessness and suffering.12

According to legend, Zon-Kuthon's domain was originally a prison constructed by Abadar to restrain the Prince of Pain. When he was released due to a technicality, he reformed Xovaikain into his own domain.3

From the outside, it resembles a great obsidian wall jutting out from the ground and into the clouds above. Almost nothing is known about Xovaikain's gloomy interior, and only the cacophony of screams from within provide any insight about the horrors inside.4 Rarely, a tortured shade "escapes" the shadowy walls for a brief moment before being drawn back inside by dark tendrils. The Prince in Chains, Zon-Kuthon's herald, prowls the steel labyrinth for new victims.5


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