Obito Uchiha is a character from Naruto who hails from the Land of Fire, but there is no flame in his heart or lungs. He embraced the Curse of Hatred, which is a contrast to the Will of Fire. This distinction will be the death of him.
Will of Fire, no matter what form it's in, is a pivotal trait several characters possess that prove vital in helping them defeat Obito. The world of Naruto leaves no innocents behind as it delves into the darker side of humanity, though ideals can be challenged and even changed at times.
10 Naruto characters who defeated Obito with the Will of Fire
1) Rin
Rin is a vital contrast to Obito in terms of belief. She embodied the Will of Fire so much that she let herself be killed by Kakashi in order to save the village. Her Will was absorbed through the skin despite the Third Tails slumbering beneath and so she allowed her body to be ripped through.
She was his downfall because of his love for her. Obito fell in love with her, and thus he fell for one aspect of the Will of Fire. His Curse cannot coexist with her Will unless he abandons her, which he never will. She was a large reason on why he went back to the good side in the fourth war as her influence over him was too much to bear.
2) The Uchihas
The Uchiha's themselves are the product of their own destruction, as commented on by the second Hokage. They're a strange bunch who value and deny emotions so greatly that their power heightens. They embody the Curse of Hatred to the extent that their minds cannot be reasoned with.
Their emotions spread into insanity if they linger too long in their melancholy, but no one is sure how to combat them. Obito was trapped in the delusion of the Curse, but it was his downfall because he was unable to see reason until it was too late. By the time he saw the Will, he was already lost.
3) Kakashi
Ironically, Obito changed Kakashi's will. He used to prioritize only the mission, and thus Konoha, until Obito told him that his comrades mattered just as much. This was part of his downfall as Kakashi took his words into consideration and prioritized his friends.
Obito proved to be another way to extend the Will to him. He gave him his Sharingan, which enhanced Kakashi's already prodigious traits and elevated him. Itcwas equivalent to giving a tiger a sword. Later, Kakashi was able to defefeat him with the help of Naruto. Ironically, Naruto was his student, so he absorbed his teachings and became the final blow to Obito's ideals.
4) Madara
Madara Uchiha's Will was an entirely different matter. He thought the ends justified the means, and at first Obito thought nothing of it. Madara forced the Third Tails into Rin, which ultimately led to her death, but this event caused Obito to embrace the Curse of Hatred.
Madara encouraged it as the Curse complemented the Will as if their ideals were closely related. Despair was just as good as valor to the cause. Madara was his downfall as his ideals blinded Obito until he was near the end of his life.
5) Minato
Minato was the personification of the Will of Fire itself as he was the Fourth Hokage. He was the teacher of Obito who influenced him during his younger days, as well as Naruto's father. Obito and Minato's battle during the Nine Tails' attack proved just how far was he gone.
Obito intended to destroy the Leaf using similar methods to Madara, though he had no way of knowing. Minato's defense of the village frustrated him to no end. During the war his Will shook him to the core. Add to the fact that Naruto inadvertently gained the Nine Tails through him and somehow tamed it, he tampered with more than just fate.
6) Sasuke
Obito was interested in Sasuke since they shared the Curse of Hatred. Whereas Sasuke wanted to destroy the Leaf, Obito wished to change the world. He changed Sasuke's ideals to the point of him simultaneously possessing the Curse and Will of Fire. While Naruto was his opposite, Sasuke was seen as his equal.
This was his downfall as his interference in Sasuke's life gave him the opportunity to help defeat Obito. Inserting Itachi's eyes inside him gave him a newfound perspective and abilities that he could not have predicted.
7) Black Zetsu
An unusual case, as Black Zetsu's ideals contained no Will of Fire or Curse of Hatred. It presented itself as an arrogant manifestation of Madara's Will when it really took no sides besides its own. When Obito regained the Will of Fire, it possessed half of his body.
This was Obito's downfall as he really should have seen it coming. Even without knowing its intentions, Black Zetsu was able to overpower Obito as he knew the latter's abilities beforehand as he had trained with Obito for years.
8) Sakura
She is another unusual case in Obito's case. She doesn't hold the Will or the Curse as her priorities lie elsewhere. When Obito tells her to take his eye before Madara comes, she hesitates and fails to accomplish this task.
However, Rin immediately performed the needed surgery as she knew there was hardly any time left and had to return to the village. Sakura, on the other hand hesitated as he was nothing more than a villain-turned-ally. This contributed to Obito's downfall.
9) Kaguya
The alien who dealt the final blow to Obito also had no ideals. She was unsealed and saw Obito as a nuisance. At that point he had regained the Will of Fire, but even he could not face a god.
His defeat stemmed from the fact that he joined Madara in the first place. He let the Curse consume him to the point where he didn't question him nor Zetsu, despite their overall craftiness.
10) Naruto
Natuto embodied the Will of Fire to the point of scariness, maybe even more than his father. He and Obito grew up alone and both strived to become Hokage just so that the village would acknowledge them. Naruto loved the village despite its shortcomings.
Whereas he embraced the Will of Fire and never let hate overtake him, Obito's bloodline encouraged him to seek the path of anger. Obito sought to destroy Naruto as he was reminded of his younger self. Ultimately, Natuto defeated him with his ideals, in which he submitted himself to defeat.
Ultimately the ideals of the characters led to the defeat of Obito, but Naruto was the cumulating factor of the ages. Naruto was merely the forgotten son of a prestigious ruler and was abused everyday for wanting to better himself. He sparked the Will of Fire in everyone, including Obito.
The manga and anime of Naruto emphasizes the real world connection of dying for one's country as well as honoring comrades. It's not just a tale of woe, but a depiction of the sacrifices the characters made. Naruto, as a series, is undying.