Geists of Discord

Geists are strange and unnatural creatures who are somewhat incorporeal. During daylight hours, or when light is present, they  flatten themselves onto vertical surfaces, appearing as a stain or shadow  composed of soot. In this state, they  are impervious to any sort of damage, and it is difficult to tell the difference between them and a dirty wall. Only the smell they produce in this state gives them away. A mild smell but  distinctive, reminiscent of rotting eggs and dried blood.  When darkness falls and the shadows become long,  Geists detach themselves from whatever surface they are on, appearing to float  silently above the ground. In this form, they are composed of what appears to be dark smoke and flitting robes, with large cold hands extending from where the hands would be on a normal person. Upon closer inspection, one can see teeth protruding from the edges of the robes, almost as if they  entirely  consist of one giant mouth.  When attacking, Geists  attempt to grasp their prey and envelop them, covering the victim completely except for their legs. Once captured in this manner, the Geist seems to take possession of their target, moving around with the remnants of their body while they slowly consume them. This is a horrifying visage, and many scavengers have been driven mad as they have watched their companions be killed in this manner. While the Geists are incredibly disturbing and dangerous while possessing a body, it is also the time that they are at their most vulnerable. When a possessed body is burnt to ash the Geist that was attached to it is also destroyed, or at least driven back to whatever nightmare it sprang from.