Firstly, I appreciate I haven't identified myself as a Psi Vamp - or any other type of vamp - as yet, but after reading the thread, I have to agree with the points made by a few others.
The core definition of a 'Vampire' is such that it is believed to remove from someone something whch sustains them, whether it be blood, life energy, money, food, or something else.
In this instance, as pointed out a Psi-Vampire takes energy rather than blood, and whilst they aren't drinking bolod in what is seen the 'traditional' sense of the word 'vampire' they are usually obtaining the same type of boost to their energy through consent (but rarities of stealing something) from someone else.
Whilst people may not like the term I feel that Psi Vampire or Psi Vampyre is appropriate since you wouldn't call them Psi-Leecehers since they would drink blood
