She seeks vengeance for the wrongs of her life.
Nu gui are the ghosts of women who committed suicide, especially those who were wronged or abused while alive. As ghosts, they are draped in long white or red dresses, with flowing black hair. They take their revenge upon the living, sucking out life essence as they wreak their revenge. They often go after lecherous men, seducing them and then leaving their corpses behind. Very little esle is known about them – perhaps because few have survived their scorn!
Image from The Beijing Family