After Escaping the Castle, I Lit the Sacred Fire

In the fifth century AD, East and West Rome was divided, and wars raged on the borders. Leon, a border boy, strayed into the ancient forest to avoid massacre, and was captured by the vampire girl Selina and branded with the mark of a blood slave. He secretly learned vampire magic under oppression, broke the contract and fled to Constantinople. Here, he was selected by the fallen angel Lucifer disguised as the "Holy Lord", who used his psychic physique to transform him into a human and recruit him into the Holy Knights. However, the Holy Knights are actually pawns used by Hell to infiltrate the human world. With the help of the noble girl Hepburn and the sacrifice of the archangel Gabriel, Leon saw through the conspiracy and fled to Western Rome to become a bounty hunter. After experiencing the tribulations of the werewolf tribe and studying at the British Isles Magic Academy, Leon finally awakened the "Heavenly Holy Fire" power. When Lucifer united with the ancestor of the vampires (Selena's grandfather) to open the gate to hell, Leon led a resistance army composed of vampires, werewolves, and mages, and launched the final god-killing expedition at the tragic cost of losing two-thirds of human civilization.