Spectre

The more powerful a soul has been in its lifetime, the more powerful it will be as a ghost. The more malicious and intelligent a soul has been in its lifetime, the greater the variety of powers it can demand as a ghost. For most ghosts it takes great effort to maintain some sort of sentience. Most end as drifting memories of the past, driven by emotions they do no longer understand. But some sinister beings are aware of the fate that looms above them. They research forbidden knowledge and forge dark pacts in time. This allows them to rise as a sentient and powerful form of ghost, known to those with mystical knowledge as Spectre. Spectres usually posses some being that functions as shell that they have prepared during lifetime. Often they use beings to which they have a strong emotional bond like family members. In the long run, the Spectres' puppets die away and leave the Spectre stranded in the world of mortals without a suitable host. Some succumb to madness when recognising it, others turn their frustration into hatred towards humanity. Being enemies of all things alive, they both pose a great threat to mortals.