Daayan

A Dayan, Dain, Daini or Daayan is a type of witch found in India. They are a practitioner of black magic that deal with the Dakini, creatures from Patala (the netherworld, and similar to both the Succubae & Vampires. Powerful & older Daayan are usually referred to as Ekayan. The Dakini has been mentioned in numerous ancient Hindi texts such as the Bhagavata Purana, Brahma Purana, Markandeya Purana, and Kathasaritsagara. They are also found in Nepal, Tibet, China, Japan, and Mongolia.
According to folklore the Daayan is found in an area of a village, and will bring destruction to the village. Cemeteries, abandoned battle fields, crossroads, toilets, and squalid places are associated with them. They are women treated badly by their families, or dies during childbirth resulting from neglect or abuse by the family. They come back and start to feed on the youngest make, draining him of blood or life force until he prematurely ages, dies, and then the Daayan moves on to the next youngest male. There is stories of them targeting young families, young women or other surrogate families. A few state they wait at crossroads, seducing young men and feeding on them in a sexual way.
They are sometimes thought of as having monstrous black nails, and a primary source of power is their long plaited hair (called "choti"), and acts like a third limb for them. They can cast an Evil Eye cursing not just the specific victim, but also the victim's whole family. Sometimes they are mentioned to have their feet pointing backwards.
A problem with them is that they are thought of as a paranormal creature, and other times as a witch with the power of the demonic (in this case a Dakini). It is likely they are just witches or some type of Warlock that have made bargains with the Dakini for their powers, and the Dakini affects their looks when they use magic. Also, the Dakini could possibly use the Daayan as an anchor point to come through to the Material Plane to feed on the blood or Life Force of the living.
Daayans are thought off as handmaidens of the evil black magic spirits & goddesses, and are sometimes referred to as yoginis. They and their spirits are sometimes likened to the vengeful ghosts referred to as Churel.