Cain was a human who got accidentally killed, then turned by Eve into a vampire. Overcome by anger, he got into a blood frenzy until Eve prevents him from killing Ange, his former classmate. Cain understands that Eve is ready to share his cross, but they got separated by Tristan, of whom Cain is horribly jealous.
Cain had been appointed by Mayor Yu Wong as intermediary between the vampire community and the government. More focused on his personal issues, he did a poor job out of it, going as far as escaping with his daughter Eloise. Cain is very protective towards Eloise, but lacks the experience and perspective to deal with her very special powers.