A vampire is a person possessed by the lust for vengeance. That spirit is notably difficult to kill or banish. The young and innocent are particularly susceptible. Once you invite it into your home, it can always return. Of those completely possessed by it, one can say "on reflection, there's no one there". It thrives in the unexamined dark and cannot abide the full light of day.
To Phil, who asked for a definition of "vampire":
A vampire is a person possessed by the lust for vengeance. That spirit is notably difficult to kill or banish. The young and innocent are particularly susceptible. Once you invite it into your home, it can always return. Of those completely possessed by it, one can say "on reflection, there's no one there". It thrives in the unexamined dark and cannot abide the full light of day.