Echoes of Injustice

Should someone meet an untimely demise that is particularly violent, unfortunate or was otherwise significantly helped by a third party (usually some sort of a greedy murderous bastard), the powers of the Underworld, under the domain of the slain god Naru, can decide that this spirit shall not be taken from the mortal world just yet. Instead it is left there to haunt and screech their way until the past crime is appropriately avenged.
The Echoes of Injustice are seen to be the most menacing and dangerous, wrathful and volatile, of all paranormal sights and can definitely endanger anyone who remains within their vicinity. They can haunt you and your bloodline for generations and centuries and will not cease until their plight is rectified. They can drive people mad with their incessant everpresent voice or force them to do something they wouldn't otherwise do. Flying objects, destroyed furniture and many other things associated with paranormal sights are also well established within their repertoir. They are seen as a part of punishment for people who are continuing to give voice to the darkness and listen to them to commit evil deeds.