Alukites

 (also known as Empousai or Soucouyants) are monstrous beings who were once Long or greater. They are mostly, but not entirely female. They have wings, but look human until they shed their skins. They are found on Raven Isle and the Ascent of Knives. They are not often observed to blink, or to cry. Sulochana Amavasya is an alukite and a member of the Ligeia Club, an organization of especially powerful Alukites able to elevate Long into Names by virtue of holding special Keys to the Mansus.

Crime of the Sky
Alukites are produced by the Crime of the Sky, a forbidden act very strongly implied to be eating one's children. Many sources suggest that if Long (and higher beings) have children with other Long (or higher beings), they become subject to a nearly-irresistible urge to eat their children. This leads nearly all such beings to avoid heterosexual intercourse, from the Obliviates (who forbade it on pain of death) to the Hours themselves. The Law which produces the Crime of the Sky is - like all natural laws - part of the wills of the Hours. As such, it may be enacted in order to restrict the number of immortal beings by limiting their reproduction. The Dream of the Conspiracy of the Lower Skies implies that an Hour turned Alukite would be a nearly unstoppable force of destruction.

Sources on the Crime
The Dream of the Conspiracy of the Lower Skies suggests that alukites are made when a being commits "the Crime of the Sky", and that the Hours refrain from satisfying certain passions as a result of their fear of it. The Crime is also referenced by The Silver Book, which deals with the Obliviates' prohibition on heterosexual intercourse, as a "furious danger" which may result from such relations. Exploring with the Atlas of Dreams additionally refers to this prohibition as being motivated by the avoidance of "the sin of the empousai".

Five Creations states that consuming one's parents is not the Crime of the Sky. When obtaining influence in the Red Church, the Names of the Red Grail say the following:

"Not all the empousai are women. The hungers of women run no deeper than the hungers of men. But a mother is never far from her child at its birth, and that is not always true of a father."

- Grail-Names

In the Apostle victory, it is stated that the Vitulation could be achieved by the Delight consuming one of their own children, but that this would constitute the Crime of the Sky.

In dialogue from the Lodge of the Sage Knight, Teresa implies that the reason Christopher Illopoly did not ascend along with her was so that they could continue their relationship without risking the Crime of the Sky.

Real-World References
The world "alukite" is probably derived from the Hebrew Alukah, "horse-leech", which can refer to a human who shape-changes into a wolf and drinks blood. Empousai are creatures from Greek mythology with one leg which drink the blood of young men. Soucouyants are blood-sucking hags from Caribbean folklore who appear as old women by day and as fireballs by night, and can assume the skin of their victims.

The Crime of the Sky may be inspired by, or an oblique reference to, the myth of the Titan Cronus. In Greek mythology, Uranus was the first god of the sky, and the father of Cronus. After Cronus usurped Uranus, it was foretold that one of his children would do the same to him. In order to avert the prophecy, he ate each of his children after they were born.