system
Given the following post, respond as if you're commenting on Reddit:
human
[LoTR] Galadriel accepts the Ring from Frodo. What happens next?

"Instead of a Dark Lord you would have a Queen! All would love me and despair!" 

What does that mean exactly? Super mind-control powers? How would the rest of the White Council, Saruman or even Sauron react for that matter? Has Gandalf been resurrected yet or would he be returned even more powerful to combat this new threat? Could Mordor and Rivendell even join forces if this new threat was so terrible? And if she wins this new War of the Ring, what would this new Galadad-ocracy look like?
gpt
According to Tolkien's letters, if Elrond or Galadriel took the One Ring they would have used the same general strategy as Sauron was using: "they would have built up an empire with great and absolutely subservient generals and armies and engines of war, until they could challenge Sauron and destroy him by force." While her control would be incomplete, Galadriel would be able to use the Ring's ability to influence and dominate the minds of others (especially those connected to the Rings of Power) to a much greater extent than Frodo or Sam ever did.

Sauron would be seriously worried, and would probably send his armies against Lothlorien as soon as possible to prevent them from becoming strong enough to challenge him. (This is also why he responded to Aragorn's attack on the Black Gate; he suspected Aragorn or Gandalf had the One Ring and had arrogantly decided to attack Mordor directly.) If it ever came to a direct confrontation of wills between Galadriel and Sauron over the Ring, Sauron would win. Sauron is not only incredibly powerful but also the rightful owner of the One Ring, and that counts for a lot in Middle-earth.

Saruman would be even more worried than Sauron, since both sides deeply distrusted him and the possibility of stealing the One Ring was pretty much the only hope he had. Who knows, he might even pretend to side with Galadriel in the same way he pretended to side with Sauron.

Gandalf actually returned to life on the same day that Frodo offered Galadriel the Ring. It's hard to say what he would do; he usually tries to confront even enemies who seem completely lost (as with Saruman in Isengard after the ents attacked), but it would be potentially dangerous to enter Lothlorien with Galadriel in possession of the Ring. There's also the fact that Gandalf himself has one of the Three Rings, so it's quite possible Galadriel could exert some influence over him. (Rivendell is also in trouble, since Elrond also has one of the Three.)

Even if Galadriel did conquer all her foes, she would still become irreversibly corrupted by the Ring. She would never willingly give up her power. Like with Sauron, she would at first want to have authority to order things for those who have less power or wisdom; later, this goal would become lost beneath the desire of power for its own sake. Her own power combined with that of the One Ring would make her presence and sense of authority so awe-inspiring that none could oppose her (as she says, "beautiful and terrible as the Morning and the Night!"), but she would still be an autocratic despot running what would quickly become a police state.