He is similar in appearance to Hell level Diablo and is a formidable challenge. So you can basically choose the location to fight Uber Diablo by selecting which super-unique you want him to replace. He will spawn at the first super-unique monster you encounter, Eldritch the Rectifier, Bishibosh, Rakanishu and even Corpsefire in the Den of Evil. This message means that Über Diablo has spawned. Once a certain number of these rings are sold, the whole screen shakes and the words 'Diablo walks the earth' appear on the screen. A notification is displayed onscreen whenever a Stone of Jordan is sold, indicating the number that have been sold. Über Diablo is a monster that spawns only on Hell level games on when a certain number of Stone of Jordan Rings are sold to merchants.
