Crimson Cross (manga)

Karl is a holy vampire hunter from an infamous Van Helsing family…who’s been turned into a vampire himself. Though the evil Elliot now knows the taste of his mortal blood, Karl has somehow retained the faintest sliver of his humanity. How long will Karl’s tortured soul continue to waver between shadow and light? And are he and Elliot doomed to try to destroy one another…for eternity?