I once had a character in the previous incarnation of 218, who could perform psychic feats through psionic apparitions that only he was able to see. His connection to them allowed a form of telepathic immunity, in that if anyone tried, the apparitions would sense an invader and start screaming and screeching into his head (and thereby affecting the telepath as well). This happened once. Both characters were squirming on the ground crying and screaming for it to stop as their ears were bleeding.

Man, good times.