In the fanfiction, Itachi might be acting according to some secret mission that endangers Sakura's life. Sasuke, who has a strong bond with Sakura now, won't let that happen. He jumps in and uses his ninja skills. Sasuke could have developed some new jutsu that he uses to counter Itachi's attacks. This not only saves Sakura but also shows Sasuke's growth as a ninja. And Sakura, in turn, might be in the middle of researching some important medical ninja stuff that Itachi's actions could have disrupted if not for Sasuke.
Sasuke's character could develop in terms of his loyalty. By saving Sakura from Itachi, he shows his loyalty to his friends and comrades. He is no longer just the revenge - driven Sasuke. He has grown to care about others' safety.
Sure. Itachi's saving of Sasuke was a crucial moment in the manga. It was tied to his hidden motives and sacrifices for the greater good of the ninja world and Sasuke's future.
I think young Sasuke would have a very intense reaction. He was so consumed by his hatred for Itachi at that young age. A Sasuke vs Itachi fanfiction would be like a trigger for him. He would be eager to see how the fictional fight is portrayed. If Sasuke in the fanfiction is shown as strong, it might fuel his own ego and make him strive even harder to become powerful. However, if the fanfiction shows Itachi as superior, it could enrage him. He might feel that it undermines his own goal of defeating Itachi and he might even want to find the writer to correct their 'wrong' view.
A possible fanfic could focus on a parallel universe where Itachi and Sasuke are not bound by the same clan conflicts. In this universe, they could meet in a more peaceful setting, like a small village. Their relationship could develop gradually as they discover shared interests. For example, they might both be interested in learning about ancient ninja arts, and through this common ground, a yaoi - inspired relationship could start to form.
In fanfiction, Sasuke and Itachi's brotherly love is often depicted in very complex ways. Some stories focus on Sasuke's journey to understand Itachi after his death. He discovers the truth behind Itachi's actions, which were all to protect him and the village. This realization deepens his love and respect for his brother.
Fanfiction.net is also a good place to search. However, the tagging system might not be as detailed as AO3. But if you dig a bit and look through the Naruto section, especially in the Itachi and Sasuke character - centric stories, you may come across such a fanfiction. Some writers might be more subtle about it and not have the kiss as an obvious part of the title, so you'll need to read the summaries too.
One possible plot could be Itachi saving Sakura from a powerful enemy during a battle. Maybe she was outnumbered and Itachi showed up just in time to use his Sharingan skills to turn the tables.
Itachi is known for his loyalty to certain ideals. In the context of saving Sakura, he would be the reliable figure. Sakura has her own set of skills as a medic - ninja. However, in the dangerous situations where Itachi saves her, she is more of the damsel in distress for that moment. But this experience could potentially change her approach to future challenges.
In many Sasuke - Sakura - Gaara fanfictions, Sasuke saving Sakura from Gaara can be a really exciting plot. It often shows Sasuke's strength and his hidden feelings for Sakura. Maybe he uses his Sharingan to outwit Gaara's sand attacks and rescue Sakura just in time.