The Shackled City
According to Kaurophon, Adimarchus was a fallen angel turned demon prince who used to rule over Occipitus. He was known to be in feuds with Graz’zt and a number of other Abyssal lords and vanished from history over fifty years ago. Saureya later confirmed that Adimarchus had been a planetar before his fall, and had vanished during some pointless battle against Graz’zt’s forces. He is presumed dead.