Sophus- "Governor" of the City of Dis (the opulent city found in the Circle of Heresy)- is a much older demon than he initially appears to be, and is in fact one of the original Fallen Angels from Satan's rebellion, though they do not flaunt this fact like many others do. Instead, Sophus merely wants to be acknowledged as equal to any other Heresy demon, and takes great pride in his Circle. In fact, although he had the choice to join the deepest Circle of Hell (Betrayal) thanks to his status as Fallen, he refused, specifically requesting to become a Heresy demon instead because he particularly enjoyed the idea of digging into the minds of others to see what makes them tick and then using that very knowledge to unravel them and even change their belief systems. Satan was pleasantly surprised by this ambition and dedication to Heresy, and thus awarded Sophus the title of Platinum-rank Heresy demon. 

     Since then, Sophus has had many children (many of them also notable Heresy demons), been responsible for the fall of many angels from Heaven, and is generally considered to be one of Hell's foremost experts on the art of both hypnosis and persuasion, making them incredibly well-respected in both Heresy and in wider Hell alike. Part of the reason for Sophus's long-held position is because they have no real enemies in Hell to try and take them down, primarily due to two factors: 

1) Their style of leadership is quite community-based, and they run Heresy as more of a team effort with some of the other higher-ups of Heresy. This means there is little competition in Heresy, and Sophus's flock protects him.

And,

2) Even if Sophus DOES make enemies, they can easily convince the other side out of it, even erasing the aggravating memory entirely.

     Sophus is fascinated by the minds of others, and can sometimes even act as a sort of therapist/psychoanalyst to other high-ranking demons that can afford his services. Though they may help some with this service, they also toy with the minds of many others, and they take special joy in shattering the hope and faith of angels- adding them to the ranks the jaded in Hell.