Kasdeja — sometimes spelled Kasdejah or Kasbeel — is named in 1 Enoch 69:12 as another of the Watchers whose particular teaching is indicted: 'And the fifth was named Kasdeja: this is he who showed the children of men all the wicked smitings of spirits and demons, and the smitings of the embryo in the womb, that it may pass away, and the smitings of the soul, the bites of the serpent, and the smitings which befall through the noon-tide heat, the son of the serpent named Tabaet.'
The catalog is grim and specific. Kasdeja's curriculum, in 1 Enoch's framing, includes the manipulation of spirits, the destruction of the unborn, and divinations meant to harm human bodies and souls. The cumulative picture is a technology of harm — a knowledge of how to wound a person at every level of their being.
The Christian inheritance does not treat 1 Enoch as canonical, but the figure of Kasdeja is part of the angelological background the New Testament inherited. Scripture's consistent prohibition of divination, sorcery, and the harming of the innocent is not arbitrary law but reflects a real spiritual conflict: the technologies that destroy human flourishing have, in the older biblical imagination, a real source in beings that taught them outside the covenant of life.
The arts Kasdeja taught for destruction are undone in Christ, who came that men might have life, and have it more abundantly (John 10:10).