They sip energy from their victims, they dominate people and use shadow beings to spy for them. Shadow beings also can negotiate when both sides want or need.
I've learned a spell, Summon Creature IV, spell that allows lawful good people to summon Being of Light, also called Lantern Archon. This summon spell also allows for summoning small xorn creatures.
Being of Light can protect one from shadow-spies, as it is stronger than shadows, as light that disperses the dark. Being of light can be used to spy or negotiate as well, but is worse at spying than shadows.
Lantern Archons also have some power over electricity and lightning, and are quite resistant to physical damage from nonmagical sources.
Not all psychic vampires are bad, some are our allies and use their powers responsibly, mostly to recover energy stolen from us.
-- Crystal.

