Ghost king in the underworld (Half-Ghost Male reader x Highschool DxD)

The terror of Dan phantom was everywhere, there were no ghosts who could defeat him, he was the ultimate enemy to humanity. Vladimir Masters was a desperate man, the guilt of the monster he had created weighed heavily on him, so he decided to do something about it. Now that he no longer had his own ghost powers, and no other ghosts were a match, he decided to make a choice, that would later change the course of the supernatural history, of one of their timelines.