An ancient relic of Sith sorcery, Pax Noctem is a manipulation of the Dark Side of the Force that requires bare competence to perform - but absolute mastery to perform without ruining oneself in the attempt. The Sith Acolyte taps into the traumatic memories of past experience, recalling the sensations attendant with that memory and projecting them outward. The area of affect is dependant on the user's connection to the Force, and the intensity of the result is determined by the forcefulness of the user's memory.
The end result however, manifests as all within the area of effect experiencing sensations of panic, suicidal despair, helplessness and the utmost terror. Records tell of ancient Sith Lords engulfing entire worlds in the Pax Noctem, resulting in mass suicides, the death of animals, the young and the old by immediate cardiac arrest, and the withering of entire forests.
The drawback to this Sith spell is that the user is engulfed in the heart of this sensation - because the memories and emotions are her own - she experiences everything with twice as much clarity as anyone else does.
Only one Force user, the Sith Lord Seth DeSchaen, has been known to successfully apply this spell with no adverse affect on his own mental state. It is unknown how he has managed to do this.