Grioza

A grioza is a nightmare spirit, which can suck the life-force out of a living being by passing through or simply touching them, or cause mischief by throwing living creatures against walls an solid objects.
Griozas are insubstantial, and cannot talk, though they can gesticulate. They tend to haunt particular locales near which they died. There are suspicions that they may spirits of dead nechist'.
Plamen's mother Plamenka because a grioza after she was brutally killed by Lionia and his companions.