In the Zadokite Fragments and Dead Sea Scrolls, he is the angel of disaster, the Father of all Evil, and a flatterer of God. According to the Book of Jubilees, Mastema is the chief of the demons engendered by The Watchers with women. When God is ready to destroy all these demons after the Flood, Mastema intervenes, beseeching God to allow him to retain and control one tenth of these demons in order to exercise his authority because they are "intended to corrupt and lead astray before my judgement because the evil of the sons of men is great". So Mastema is the tester of humans with God's permission.