Abaddon

A direct descendent of Lady fierna of Phlegethos, is known for having striking beauty as well as a murderous fierceness. 
A mighty warlord who was one of the head commanders in the blood war as well as partial warden for the prisoners of outsider within the 8 realms of hell. Over his long lifetime he sired 20 children, their favorite of which was their eldest Samael, the twins Mania and Mantus, Samnu, Nergal, and their youngest son Bartzabel (who has unbeknownst to him changed their name to Ash). 
Though Ash is actually a tiefling which makes them a half-blood, Abaddon took special interest in shaping Bartzabel’s growth so believing they may be useful in any potential subterfuge of the material plane as there are some populations of tieflings where they could blend in. While they had let Bartzabel do much of what they liked when they were a child, they began to realize this was a slight mistake as they were a rather soft child. As Bartzabel started to grow into an adult, they became cruel and critical and kept a mostly diligent eye on them as they were made to work as a torturer in the prison. While Abaddon was proud of Bartzabel, he would never admit it to him. 
Since their capture by the damned adventuring party from the material plane, Abaddon has not given up hope that Bartzabel may still be alive. While he has had no informants return with any good news, he believes his son will be at his side again soon. Abaddon’s whereabouts from the end of the blood war are unknown.