Cain

the first human turned demon
Brother of Abel
Given a mark by Lucifer to help channel the malice that now flows through him. This mark became known throughout all the realms of hell as the mark of Cain. The mark allows Cain access to the same source of power that Lucifer draws from, because of this it is long sought after by many demons looking to gain the strength of their once king.
Cain as part of Lucifer’s court was known as a Knight of Hell the equivalent to mathael’s sins. Cain used his power to keep the demons in line and limited their presence on earth. When Lucifer abdicated the throne, Cain guarded the court room for a time. This prevented many upstart demons from seizing the power vacuum left behind by Lucifer. Thanks to Cain there was a period of around 100 years where hell fragmented itself into even more realms, each with their own governing parties. When Cain decided to destroy the throne after 100 years defending it and then witnessing the downfall of hell, Cain journeyed to the farthest reaches. There he claimed his own little territory of hell and has remained there ever since. Many demons have ventured to find this legendary warrior and challenge him to steal his mark, only to fail.
There was one young demon who came to train under Cain. His name was Salazar. Cain caved and trained Salazar. When the day of Salazar’s “graduation” came and Cain bestowed the mark, Salazar couldn’t handle that much power.
After this event Cain became even more recluse and placed a barrier around his territory preventing any who even tried from reaching him.