In the final battle, Thorin fights Azog with Orcrist, which he recovers from Legolas. Azog attempts to stab Thorin, but is prevented when Thorin uses Orcrist to block his blade. In the end, Thorin gives in, and is stabbed by Azog.
After holding back Azog, Thorin gave in and was mortally wounded. Mortally wounded during the battle of Fire Armies. In the book, it was by the lances of Bolg's bodyguard trying to get at Bolg.
Thorin was the rightful heir to the throne as his grandfather had been King under the Mountain. But he died in the Battle of the Five Armies. Fili and Kili were also heirs after him but they also died defending him in the same battle.
After the death of Thorin in the Battle of Five Armies, Dain becomes King under the Mountain. He redeems the Arkenstone from Bard with a fourteenth of the treasure, which is used to re-establish Dale. Over the next three years, Bard rebuilds the city of Dale and becomes its ruler. The city begins to prosper again.
With Thorin's death in the battle, Dáin became King of Durin's Folk and King under the Mountain, the first not of the main line. After the battle, Dáin thanked the Great Eagles for their timely intervention, crowning their chief with gold and swearing the Dwarves to everlasting friendship with them.
Their deaths and Thorin's did not end Durin's line, although did end the branch which had Thror, Thrain, and Thorin Oakenshield. Thorin's cousin, Dain Ironfoot, became King after Thorin's death. Dain's son, Thorin Stonehelm, became King after Dain died in the Battle of Dale. The line continued on after that.
Thorin apologizes to Bilbo, saying that the world would be a better place if only more folks were like him. He asks for Bilbo's forgiveness. He bids farewell, and dies. Bilbo cries over the loss of Thorin – but is so glad that he made it in time to say goodbye and to make amends before he died.
The biggest blow to the dwarves is that their king Thorin lies mortally wounded. He forgives Bilbo before dying and lets Bilbo know that he was right all along. Thorin is replaced by Dain as king, Bard rebuilds his town, and Gandalf and Bilbo head for home.
Why does Thorin dislike Bilbo? Thorin and Bilbo have worldviews that are diametrically opposed. Hobbits value the comforts of home and festivity, while dwarves seek riches and battle. Throughout their journey, Thorin continues to undermine Bilbo, despite Thorin's own lack of preparedness and clear leadership views.
Fíli and Kíli were Dwarvern brothers and were also the youngest of the thirteen Dwarves who set out with Thorin Oakenshield's company, along with Gandalf and Bilbo Baggins, to reclaim the Lonely Mountain from the dragon Smaug.
Tauriel was banished from Mirkwood by Thranduil, so what happens to Tauriel after the Battle of Five Armies remains unknown, although actress Evangeline Lilly stated in an interview that Tauriel returns to Mirkwood.
Gimli is the son of Glóin who is introduced in The Hobbit as a member of Thorin Oakenshield's company, also being one of his four third cousins. Thorin himself is a direct descendant of Durin I, even becoming the King of Durin's Folk in his lifetime.
“Farewell, good thief,” [Thorin] said. “I go now to the halls of waiting to sit beside my fathers, until the world is renewed. Since I leave now all gold and silver, and go where it is of little worth, I wish to part in friendship from you, and I would take back my words and deeds at the Gate.”
Thorin is portrayed by Richard Armitage and Bilbo is portrayed by Martin Freeman. Fans have called them "Thilbo," but it is not canon; however this relationship is platonic in this series. An entire page was dedicated to their relationship in The Battle of the Five Armies movie guide.
Bilbo's motivations for defecting to the enemy camp are twofold. First, he realizes that the best way out of the conflict is a peaceful one. Second, despite his friendship with the dwarves, Bilbo feels more of a natural camaraderie with elves (and, to a lesser extent, with men) than with dwarves.
After the battle, the Arkenstone was placed by Bard upon Thorin's chest within his tomb deep underneath the Lonely Mountain, and so was returned to the earth at last.
Before the War of the Ring, the Dwarves took part in the Battle of Five Armies, an event covered in the third and final installment of Peter Jackson's The Hobbit trilogy. While this war ended in victory for the Dwarves, far too many lives were lost, including that of Thorin Oakenshield.
Thórin Oakenshield was born in TA 2746 and was 195 years old when he perished in the Battle of Five Armies in the book. In the film trilogy, he was born in TA 2837 and was 104 when he was killed by Azog the Defiler.
When Thorin died, he was buried with the Arkenstone. Orcrist was laid upon his tomb. The blade would glow blue if Orcs should approach; thus, they could not take the Mountain by surprise. Thorin was succeeded as leader of Durin's Folk by his cousin Dáin.
TL;DR: Thorin is half-elf, and Fili and Kili are themselves both part elf and half-human. The two young dwarves represent the union of Elves, Men, and Dwarves that once existed before Dale fell, and which will rise again.
Fíli is a Tolkien character who appears in The Hobbit and one of the sequel novels, Unfinished Tales. He is the older brother of Kíli, son of Dís, and the nephew of Thorin Oakenshield. He is a Prince of Durin's Folk who joins his uncle in reclaiming the Lonely Mountain from the dragon, Smaug.
Thorin I (Third Age 2035 – 2289, died aged 254) was the King of Durin's Folk for 99 years, succeeding his father, Thráin I, on his death in T.A. 2190. Thorin was the heir of Durin the Deathless being the great-grandson of Durin VI.
