Another way is through emotional turmoil. Maybe Naruto is going through a tough time himself and lashes out at Sasuke without really meaning to. Writers can use this to show that even strong friendships can be strained during difficult times.
Fanfiction writers could use power imbalances. If Naruto has suddenly gained a lot of power and doesn't fully control it, he could accidentally hurt Sasuke. It shows the consequences of power and the need for control in their relationship.
Some writers justify it by creating a situation where Sasuke has to make a great sacrifice. For example, he might give his life to protect Naruto or the Hidden Leaf Village from an overwhelming threat. His selfless act in these scenarios is seen as a way to atone for his past mistakes and show his growth as a character.
Well, often they use the idea of Naruto's strong will. They say that his will is so strong that it breaks the normal limits of what is possible in the Naruto universe. So, his will allows him to access these impossible powers. Also, in some fanfictions, Naruto goes through some extreme and unique training or experiences that no one else has had, and this is what gives him these extraordinary abilities. For example, he might travel to a different dimension where the laws of physics and chakra are different, and when he comes back, he has these new powers.
At first, Naruto is probably shocked and confused. He might not understand why the village would take such a harsh step just for hurting Sasuke. He may feel betrayed, especially if he thought he had friends and allies in the village.
They could also use the idea of being influenced by dark powers. Maybe Naruto comes into contact with a powerful and malevolent force that slowly corrupts him, making him do things that are out of character for the original Naruto. This gives the writer a way to explore a different side of the character while still having a somewhat believable reason for his actions.
In some fanfics, Sasuke might reject Naruto's attempts at friendship harshly. He could say cruel things about Naruto not understanding his pain or goals, which deeply wounds Naruto. For example, Sasuke might tell Naruto that he's always been a nuisance and that he never wanted their friendship, making Naruto question his self - worth.
Forgiveness is a huge part in these fanfictions. Naruto, being the kind - hearted character he is, often quickly forgives Sasuke once he sees his regret. It shows Naruto's big heart and his deep bond with Sasuke. For example, in one fanfic, Naruto just hugs Sasuke when he comes to apologize and says he never really held a grudge.
One example could be a fanfiction where Sasuke has a moment of self - reflection after a major battle. He realizes how much pain he has caused Naruto over the years. In this fic, he might start to make amends by protecting Naruto secretly or showing small acts of kindness. Another could be a time - travel fanfiction where Sasuke goes back in time and tries to change his actions towards Naruto to avoid hurting him in the first place.
They might justify it through her past traumas. For instance, if Sakura has faced repeated rejections or has been constantly overshadowed in the original story, a writer could use this as a reason for her to betray. She could feel that she has been treated unfairly and that her so - called friends never really understood her pain. So, in the fanfiction, she decides to take a different path that is seen as a betrayal to those around her.
Some writers might justify it by exploring the idea of redemption. They could write Voldemort in a way that shows a glimmer of humanity that Harry, being abused, might be able to relate to on some level. Maybe Voldemort has a hidden past that makes him more complex than just the evil wizard we know.
Writers often use misunderstandings. For example, Naruto might misinterpret Boruto's actions as being rebellious when Boruto is actually trying to prove himself. This leads to Naruto scolding Boruto harshly, which hurts Boruto deeply as he feels his father doesn't understand him. It's a simple yet effective way to show emotional hurt.