Answer:
Sauron is a flat character
Step-by-step explanation:
Plane characters are characters built around a single quality or defect. Therefore, it has no psychological depth, and does not alter its behavior in the course of the narrative. They are static characters, defined in a few words, by a trait, by a basic characteristic element, that accompanies them throughout history. It is the ironic that is always making ironies, the boring that only knows to be boring, that is, they are characters that do not present contradictions: they are always good or bad; brave or lying; lazy or hardworking.