There is said that invoking energy to help others can do harm to you and create a tie between you and the other person. Evoking energy is using energy from outside yourself. (J O S Power Meditation).
Now if someone (psychic vampire) were hungry needing energy I am assuming someone can send energy into them from the universe. You don’t have to feed them your personal energy. For example visualizing a white/gold light over their head and sending the energy into them.
Would this feed the person sufficiently?