Ally of Death Vulcan
Death Vulcan and Lilith of Darkness
Count Dracul (brother), Bloody Dracul Vampir (niece)
The Forest of Transylvania - The Greatest Enemy, Mystery of Dark Cain
Dark Cain is the primary antagonist of the second part of the Dracul arc. He is revealed to be the one who manipulated Lilith of Darkness and the other undead and demons into trying to destroy the world of the living.
Dark Cain is actually the same Cain from the Bible, humanity's first murderer who killed his brother Abel out of jealousy. As punishment for his sin, he was cursed by God, not being allowed to truly die until the day the world ends. Cain conspires with Death Vulcan to bring about this end prematurely so that he can be free of his curse.