This article contains spoilers for the Rings of Power series.
After much anticipation, the Lord of the Rings spin-off series The Rings of Power is finally streaming on Prime Video. Now, fans of J.R.R. Tolkien's books or Peter Jackson's film trilogy can see how the series adds up and determine whether the story surrounding the Second Age of Middle-earth (as opposed to the Third Age in LotR) lives up to the legacy of the much-beloved franchise.
Right off the bat, the series has been controversial with its addition of several original characters that were never included in Tolkien's original works. However, there are still some canon characters in the premiere episodes as well, including some familiar names from The Lord of the Rings. While these characters have undergone several changes from how Tolkien had initially intended, the Second Age of Middle-earth just wouldn't be the same without them.
Galadriel
Out of the canon characters included in The Rings of Power, Galadriel is the most changed so far. In The Silmarillion, Galadriel left Valinor as part of a rebellion of Elves with the ambition to come to Middle-earth and rule a kingdom of her own. Therefore, she was not allowed to return to her homeland until the end of the Third Age. She was also one of the few not to trust the trickster Annatar, for good reason, since he was actually Sauron in disguise.
Of course, Galadriel's goal for vengeance in The Rings of Power is far more sympathetic to audiences and opens several doors for her character going forward in the series. Her adamant belief that Sauron is still at large sets up the scene for her eventual distrust of Annatar, and the fact that audiences know that she is right about the lingering evil in Middle-earth creates a great deal of suspense.
Elrond
According to Tolkien canon, Elrond's parents, a couple made up of an elf woman and a mortal man, were the stars of the First Age since they were greatly responsible for the victory over Morgoth. Then, in the Second Age, Elrond proved himself with his service to Gil-galad and his eventual establishment of the haven Rivendell.
So far, the Rings of Power series sets Elrond up for his future achievements, portraying him as a diplomatic politician, studying under Gil-galad and Celebrimbor to learn how to become a great leader. His friendship with the Dwarves is not necessarily canon. Still, since Tolkien stated that relations between the Elves of Lindon and the Dwarves of Khazad-dûm were amicable during the Second Age, it isn't much of a stretch. It also creates a moral dilemma for the Rings of Power-Elrond that his book counterpart was missing.
Finrod
Rings of Power stayed true to the Lord of the Rings family tree by including Finrod, who is only seen alive for a couple of scenes in the Rings of Power premiere. This makes sense since Galadriel's brother died during the First Age in Tolkien's canon. However, the series has already diverted from Finrod's original story considerably.
In Tolkien's books, Finrod is killed by Sauron (via werewolf), similarly to his Rings of Power counterpart. However, he is brought back to life at the end of the First Age and allowed to return to Valinor because of his great sacrifice. While this could be a potential plot twist for later in the Prime Video series, Finrod has so far seemed to be gone for good.
Gil-Galad
In The Silmarillion and other works from Tolkien, Gil-galad was respected as a good king, and his relationship with Elrond was pivotal in the former's character development. In canon, Gil-galad proved himself to be among the most powerful elves in The Lord of the Rings by not trusting Annatar and even sending warnings to other Elven kingdoms to turn him away if he appeared. Of course, Celebrimbor did not listen.
So far in The Rings of Power, Gil-galad does not divert significantly from his canon counterpart. While Tolkien never mentions a conflict between the king and Galadriel, Gil-galad's knowledge that evil still lingers foreshadows the character's future distrust of the trickster Annatar.
Celebrimbor
As he is in the Prime Video series, Celebrimbor is the prince of Eregion in Tolkien's books and the doomed creator of the Rings of Power. Despite Gil-galad's warnings, Celebrimbor and his smiths fell prey to Annatar's trickery. However, the respected leader had a few tricks up his own sleeves, as he also created the Three Elven Rings in secret and hid them with Gil-galad and Galadriel.
Little is seen of Celebrimbor's character in the Rings of Power, but so far, he has played a similar role as in canon. Elrond's connection with Prince Durin IV sets up the canon relationship between Celebrimbor and Durin III in a unique way, but the series could still take their characters in several different directions.
Prince Durin IV
Technically, Durin IV is a part of Tolkien's canon, though his character received very little specific attention in any of his books. However, it is known that Durin IV was the King of Khazad-dûm during the War of the Last Alliance.
The Rings of Power establishes Durin IV as a very likable character that brings the series the kind of levity that is often associated with Dwarven-kind in The Lord of the Rings. His relationship with Elrond is a unique addition, but one that doesn't stretch the limits of imagination. So far, he is set up to be the ruling King when the infamous Balrog is uncovered, but canon dictates that that was Durin VI. With the compressed timeline, this could always be changed.
King Durin III
In Tolkien canon, Durin III is one of the seven Dwarf-lords who receive one of the Rings of Power and is therefore doomed to fall under Sauron and the One Ring's control. Until then, however, the King was known to be an ally to the Elves of Eregion and Lindon and helped them in their fight against Sauron for a time.
The version of Durin III in The Rings of Power seems to be fatigued by his rule and plagued with a distrust for the Elves, as seen in his perspective of Elrond during his visit to Khazad-dûm. While this may not necessarily be canon, it does provide the opportunity for interesting character development that was missing for the Dwarf King in any of Tolkien's books.