The dark overlord Chronicles and the death king slayer

The angels of honor and glory the guardians of Heaven and Earth came down to the mortal world to fight the dark overlord that try to conquer the mortal world and was pushed back to hell but in the heat of battle one Angel was left behind mortality wounded he cried out to his fellow angels but they ignore his cries for help
As the dark overlord was being pushed back into hell he glanced and saw the mortally wounded angel and dragged him into hell with him and convinced the Angel to become the king death slayer, the angel of vengeance and the angel had one request I want to kill all the ones that left me for dead and the dark overlord agree

The transformation. Once the angel agreed to become the king death slayer the dark overlord gave the angel the blood orb of vengeance to start his transformation.
And as the angel was transforming he started to build up his internal power for the transformation the angel started to change in appearance and as soon as the transformation was complete he told the the dark overlord that he was ready to go to the mortal realm so The death king slayer started to build up power again to finally break through the barriers of hell to head to the mortal realm To get his vengeance.