Isaiah chapter 14 is almost word for word the same as a Ugaritic text talking about a minor deity trying to take the throne of Baal . It’s used in Isaiah to make it seem as though he was talking about Nebuchadnezzar.
The isaiah writtings are a fraud same as proverbs where the 30 saying of Amenope found themselves. One can also see the writings of the righteous sufferer and the book being used as a foundation for the books of Job and Lamentations.