i'd be interested in seeing the debate as although gandalf is a Maia and galadreil is an eldar even sauron feared galadriel, Sauron himself came to middle earth before the forging of the rings of power. He came as Annatar. He wasn’t part of the Istari. There was no reason for him to conceal his powers. He had full access to his Maia powers. Yet, as stated by Tolkien himself, he immediately perceived Galadriel to be the greatest obstacle to him alive and that he endeavored to placate her, hiding his scorn for her, so she must be very powerful.