The LXX books known in the west as the "deuterocanonical" (because they don't appear in the Pharisee OT) are part of what the Apostles considered Scripture (Septuagint, LXX), and therefore inspired.
Over 90% of OT references in the NT come from LXX. The books the west calls "deuterocanonical" and the Protestants "apocrypha" do develop angeology beyond what the west calls the "Hebrew Bible."
The idea that Satan is a fallen angel is foreign to Pharisaical Judaism.
"The idea that Satan is a fallen angel is foreign to Pharisaical Judaism."
You have said this many times on this thread. Please explain this exchange between Jesus and a scribe.
Mar 3:22-24, "And the scribes which came down from Jerusalem said, He hath Beelzebub, and by the prince of the devils casteth he out devils. And he called them [unto him], and said unto them in parables, How can Satan cast out Satan? And if a kingdom be divided against itself, that kingdom cannot stand."