Mastema
Mastema (Hebrew: מַשְׂטֵמָה Mastēmā; Ge'ez: መሰቴማ Mesetēma), or Mansemat, is the demon or angel who appears in the Book of Jubilees. He pleads with God to permit the spirits of the dead Nephilim to remain on Earth, so that they can corrupt and lead men astray prior to judgement. Because there was great wickedness in men, God condemned all the demons to descend into condemnation except for a tenth who could remain.
In the Zadokite Fragments and the Dead Sea Scrolls, he is the angel of disaster, the father of all evil, and a flatterer of God. In some scriptures, it is said that he become a fallen angel. He first appears in the literature of the Second Temple Period as a personification of the Hebrew word mastemah (מַשְׂטֵמָה), meaning "hatred", "hostility", "enmity", or "persecution".