Thus Gandalf becomes more powerful that Saruman, showing that the ranks of the maiar are not fixed, and that the decisions and the actions taken can affect their strengths and weaknesses in relation to one another.
Saruman was a higher-ranked wizard and the leader of the White Council, while Gandalf was primarily seen as a wise warrior and counselor to Frodo. Gandalf became stronger as the White Wizard and the leader of the wizards, ultimately besting Saruman in combat due to his loyalty and growth in power and authority.
Characters who can easily defeat Sauron are; his Creator Eru Ilúvatar, his old master Melkor, and the Valar. Others who could overcome him would be Ungoliant who physically dwarfed Morgoth, and some great Maiar of Valinor described as almost as great in power as the Valar themselves.
Why Was Sauron so Powerful? (Even Among Maiar) - Middle-earth Explained
Could Gandalf beat Galadriel?
As previously stated, Gandalf is a Maia and is therefore superior to Elves regarding power. Still, this isn't to say that an elf couldn't develop enough skill and power to defeat a Maia. As a bearer of one of the Three Elven Rings (Nenya), Galadriel would have an edge against Maiar like Saruman and Radagast.
Though wizards are technically Maiar, they do not possess all the same abilities in their wizard forms. This is why, despite Balrogs and Sauron also being Maiar, Gandalf wasn't evenly matched in his wizarding form—especially as Gandalf the Grey.
In a one-on-one battle, Galadriel would likely lose to Sauron. Even though she's an Elf, both powerful and intelligent, Sauron is Maiar. Odds are, Sauron didn't fear a physical defeat — only a fellow Maia ring-bearer could physically oppose him and win, after all — but Galadriel is threatening in other ways.
He will fight in the Last Battle against the Valar and their allies, but will ultimately be slain by Túrin Turambar, the Man he cursed. By finally defeating Morgoth, Túrin will avenge not only himself, but all members of the race of Men.
Finally Sauron came out to fight Elendil and Gil-galad face to face. When Elendil fell, his sword Narsil broke beneath him. Isildur took up the hilt-shard of Narsil and cut the One Ring from Sauron's hand, vanquishing Sauron.
Most of the time that Gandalf knows Saurman he is known as Saruman the White. He was originally the chief of the wizards as well as the White Council that was formed to fight against Sauron. He was more powerful than Gandalf at these stages, but his study of dark magic turned him to support Sauron.
Galadriel's powers were so vast that it's said that other powerful beings like Saruman or even Elrond could not fully comprehend them. The powers she did have were used for good, of course, such as protecting Lothlórien and even toppling Dol Guldur, a fortress that was enhanced by Sauron's magic.
Gandalf is no mere man, but a Maiar, which are essentially the equivalent of angels in Tolkien's world. Not only that, Gandalf is capable of feats of sorcery that could easily beat back the Dark Lord. Fighting the Balrog for three days and two nights makes everything else seem like a cakewalk.
He settled in Orthanc at Isengard, both to establish a seat of power and to use the Palantír. Saruman was lured by Sauron into his service with promises of power "and became little more than the Dark Lord's puppet".
But when it becomes clear to Galadriel that Halbrand/Sauron cannot tell the difference between “saving” and “ruling” Middle-earth, she rejects his proposal. Sauron enchants Galadriel, and when she awakes, he has disappeared. We see him briefly hiking toward Mount Doom—likely to marshal the orcs and claim his throne.
Morgoth, the first to reign terror upon Middle-earth, was more powerful than Sauron and commanded an army of dragons and Balrogs. While both Morgoth and Sauron were cunning, Morgoth's rule and terror lasted longer and his corruption spread further, making him more formidable in the Lord of the Rings universe.
The majority of her powers come from her Ring of Power, Nenya, the Ring of Water. The ring, also known by the names the White Ring and the Ring of Adamant, is one of the three Rings of Power given to the Elves of Middle-earth in the Second Age.
Melkor is the most powerful of the Valar but he turns to darkness and is renamed Morgoth, the primary antagonist of Arda. All evil in the world of Middle-earth ultimately stems from him. One of the Maiar of Aulë betrays his kind and becomes Morgoth's principal lieutenant and successor, Sauron.
It was said that Morgoth hated and feared the House of Fingolfin most among the Houses of the sons of Finwë, especially Fingolfin's son Turgon, as it was prophesied that his doom would come from the House of Turgon.
As they did when the elves were first born, the Valar came to Middle-earth and defeated their brother, but this time Morgoth was cast into a void outside of existence, where he remains thereafter.
Take note, then, that at the root of Gandalf's quest is fear -fear of Sauron in particular. We are not told exactly why -but Sauron is a fellow Maiar, an angelic being who chose to follow Morgoth at the beginning.
The answer is, by far, Melkor. Melkor, or Morgoth, wanted to currupt and destroy everything good created by the other Valar. Sauron on the other hand only wanted to control and rule Middle Earth.
Sauron's quest for power dominates much of Middle-earth's history. It is his greed, however, that eventually leads to his ultimate destruction in The Lord of the Rings. By imbuing the One Ring with a part of his soul, Sauron sealed his fate by giving Middle-earth's heroes a way to destroy him once and for all.
