Mandrake is a type of magic that is conveyed through the "Psion Sound” instead of physical sound. It cannot be stopped by stopping physical sound, but waves created through magic can attenuate the "Psionic Waves" that propagate through a "Psionic Area".
The magic releases Psion waves that cause psychological damage by causing terror within 150° in front of the user. Mandrake doesn't create images of fear, but rather creates fear itself. It doesn't overload the target's emotions, yet it allows the target's consciousness to produce fear. Mandrake has no lethal effects. A target exposed to this can become a victim of intense fear leaving their mind seriously debilitated regardless of their psychological endurance. Rather, the damage can be enormous depending on whether or not the victim has been trained to endure their fears. When attacked, the fear a victim thought they had once overcome, comes forth within the consciousness which causes the victim to panic. The victim can fall into a lethargic state, or even lose consciousness. Depending on the victim, the effects of feeling the fear once again can cause it to last in their mind.
A known magic to use as partial defense against "Mandrake" is Silent Veil, which is a spell that can attenuate Psionic Sound thus weakening "Mandrake".