— alicia (@fuzzdecay) June 2, 2014
This is not to say that as far as the narrative of the films goes that Thorin is not the new Aragorn. In both cases, Jackson took an existing character and made him brooding and mopey. In Aragorn’s case Jackson also added reluctance, which is not something Thorin suffers from.
The Honest Trailer for Battle of the Five Armies exclusively refers to Thorin as “the mopey dwarf king”, so apt.
Speaking of “Battle of the Five Armies”, I am still bitter that Jackson ditched the title There and Back Again for the third movie. I could have done with a lot more denouement and a lot less of the two hour fight sequence.
So, in the films, Thorin and Aragorn are both dark, brooding heroes who are also dispossessed kings on journeys to reclaim their homeland. Beyond that, their character arcs are very different. They are even more disparate within the respective novels, but I am keeping purely to the films, as that is where this school of thought was founded.
Aragorn begins a reluctant wanderer who gets wrapped up in helping Gandalf. He leads a group of incompetent Hobbits across the wastes to Rivendell entirely unassisted. He joins the fellowship and is soon thrust into the role of leader and guide when Gandalf falls. He later begins to work in partnership with Gandalf to hold evil at bay, coming into his own as a king of Men through his prowess in battle and his willingness to engage Sauron in battles of will. Victorious due to drawing out the armies in Mordor to assist Frodo, Aragorn is crowned king, reunites with his love, and heralds the coming Age of Men.
Thorin is a prince of Dwarves who loses his home in a battle with Smaug, being left to wander with the remnant of his people. He settles in Ered Luin, builds a comfortable home for his people, and then disappears on them to pursue a suicide mission with 12 other Dwarves to reclaim the lost mountain. He also is in a fellowship with Gandalf, but unlike Aragorn who takes the lead when Gandalf leaves, what should be Thorin’s lead falls to Bilbo. Thorin becomes a bit of a liability, through consistently refusing to heed advice and getting captured. He does end up leading an ultimately fruitless attack on Smaug, who is vanquished by someone else, who is then denied any sort of thanks from Thorin. He then succumbs to sickness, leaves his kin to die, and at the last moment launches a heroic assault that lands him dead after being king for a couple of day.
Aragorn has a journey with growth and fulfillment, Thorin exists in a flat characterization of whining and being stubborn punctuated with moments of bravery.
To revisit my initial assertion that Kili is actually the Aragorn of The Hobbit, plot-wise there’s not much more to go on aside from the fact that Kili has a love interest like Aragorn, as non-canonical as it might be. I would also offer that Kili is by far more heroic than Thorin, battling against all odds with Azog to avenge his brother/save his love interest and calling his uncle on his amazingly bad decision making at the gate of Erebor in regards to the Men of Laketown, Bilbo, and leaving Dain and his army out there to die.
My main reason for this assertion is that Kili is “the hot Dwarf” — that’s the way he is marketed and presumably that’s why he has a love interest to begin with — and Aragorn was definitely “the hot Man”. They even look similar: dark hair, scruffy, and increasingly filth. There are people who also find Thorin hot, but that’s the same with Legolas, my assertion is that Thorin and Legolas are not really marketed that way. We’re not invited to view them in that romantic way given their lack of love interests. It’s harder to find the same extent of achetypes in Lord of the Rings, as there were fewer characters and they all achieved some resemblance of roundedness, whereas it’s much easier to pin one word definitions to each of the Dwarves in The Hobbit. Although I’d say that Kili is first and foremost “the hot one”, Aragorn is many other things as well that are just as, if not more, important than his attractiveness.