The Black Flames of Wrath

The story of a demon who was once human but is now dealing with becoming a new overlord and his powers of the Black Flames, but his biggest challenge is how he find way to feel something other heat or the sin he is named after. After he became a demon he fought with such rage that he earned the name Wrath and lost his old one of Jack, but can he learn how relax like his mentor and feel other things once again?