a person, Who by reason of a condition of their spirit, needs to obtain vital energy from outside sources

a person who connects with your chi (pronounced chee) or life force energy and takes it for his/her own purposes

a person who wears a mask and pretends to be somehow, that he is not

This is a term for individuals who seem to instinctively draw and absorb the psychic energies from others, usually while conversing with (or at) them.

The mythology of most cultures describe energy vampires as parasites who drain the energy or (life force/prana) from their victims. Social parasitism applied to spiritually or emotionally weak persons; those who appear to "drain" strength