The theme of justice might be present as well. If 'kina' is something evil or causing harm in the fanfic, Naruto's destruction of it can be seen as an act of justice. Also, the fanfic could explore the theme of sacrifice. Naruto might have to sacrifice something, like his time, energy or even relationships to be able to destroy 'kina' successfully.
The 'naruto destroys kina fanfic' could be centered around Naruto's growth as a ninja. Maybe 'kina' is a new threat that has emerged in the Naruto world. Naruto, being the protagonist, decides to take matters into his own hands and destroy 'kina'. This could involve battles, strategic planning, and the use of his ninja abilities. The fanfic might also explore Naruto's internal struggles during this process, like his doubts, fears, and how he overcomes them to achieve his goal of destroying 'kina'.
One possible theme could be revenge. If the writer is bashing Sasuke, they might have Naruto seek revenge on Sasuke for his actions in the original story, like when Sasuke left the village. Another theme could be power display, showing Naruto's overwhelming power as he destroys Sasuke.
One common theme could be redemption. Even though Naruto is 'destroying' Sasuke, it could be seen as a way to save him from a path of self - destruction. Another theme might be power struggle. The idea that Sasuke's pursuit of power has led him astray and Naruto, with his own power, has to put an end to it. Also, friendship could be a theme. Naruto might be doing this out of a sense of love for his friend, that he can't let Sasuke continue down this dark path.
A possible plot might involve Naruto being exposed to some ancient and powerful knowledge or artifact. This discovery gives him the means to 'destroy' bloodlines in the sense that he can change the very nature of chakra within a person. He might use this new - found ability to break the cycle of bloodline - based power hierarchies. He could start with the major clans like the Uchiha and Hyuga, and as he spreads his influence, the concept of bloodline superiority slowly crumbles, leading to a new era in the Naruto world where a person's worth is determined by their own efforts and skills rather than their bloodline.
One possible plotline could be that Naruto has a sudden and extreme power-up that makes him overconfident. This overconfidence leads him to challenge Neji in a spar that gets out of hand and he ends up 'destroying' Neji in the sense of completely overpowering him. Maybe Naruto has unlocked a new form of his chakra that Neji can't counter with his Gentle Fist technique.
Maybe in this fanfic, Sasuke has gone too far in his quest for power and revenge. He starts attacking innocent people or trying to take over the Hidden Leaf Village. Naruto, as the hero, has no choice but to stop him. Naruto could use his talk - no - jutsu at first, but when that fails, he resorts to physical combat. He might start with his basic Rasengan and gradually level up his attacks as Sasuke counters with his Chidori and other powerful jutsus. In the end, Naruto destroys Sasuke's evil intentions and either kills him or imprisons him, depending on the tone of the fanfic.
He might become a hero in the eyes of some people. But he could also be feared by others who see his power as a threat.
One possible reason could be a threat to Konoha. If Iwa planned an attack on Konoha, Naruto, as a defender of his village, might take the fight to them and end up destroying parts of Iwa in the process.
It could be that Kiba has been involved in something that Naruto considers wrong. For example, if Kiba endangered the safety of the village or their friends, Naruto, being the protector - type, would take action against him. Or perhaps there was a misunderstanding between them. Kiba might have been framed for something, and Naruto, believing the false information, tries to 'destroy' Kiba in the heat of the moment.
One possible plot could be that Naruto is somehow mind - controlled by a powerful enemy who forces him to turn on Konoha. Maybe the enemy has a special jutsu that can manipulate Naruto's emotions and memories, making him believe that Konoha has wronged him in some way.