Called the Prince of Madness, Adimarchus is the Abyssal+lord of insanity. His Realm, Occipitus, is located on the 507th Layer of the+Abyss.
His recent overthrow was orchestrated by Athux, a son of Graz'zt.
Sources: Fiendish Codex I: Hordes of the Abyss, Shackled City Adventure Path
Your innocence is treasure, your innocence is death, your innocence is all I have.
— Cross-traders' motto when dealing with Clueless