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.
Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
He might feel anger. Since he was so set on revenge against Itachi, any portrayal that didn't match his view of himself as the victor could make him angry.
Another scenario could be that Naruto and Sasuke discover a new power within themselves during the fight against Kaguya. This new power could be related to their friendship or their connection to the Sage of Six Paths. They then use this power to finally defeat Kaguya.
Most likely Naruto and Sasuke. In the original series, they were already very powerful when they faced Kaguya, and in fanfiction, they could be even more so. Their combined strength and determination usually make them the favorites to win.
Expect their friendship/rivalry to be at the center. The fight is not just about who is stronger physically. It's about their bond. In fanfiction, the writers often play with the idea of whether they can still be friends after such an intense battle. It's a very emotional aspect.
First, make sure you're familiar with the Naruto and Sasuke relationship in the original manga or anime. This will help you better understand and appreciate the fanfiction. Second, don't be afraid to try different genres within the Naruto vs Sasuke fanfiction. It could be action - packed, angsty, or even have a touch of romance. Third, pay attention to the writing style. A clear and engaging writing style can make a huge difference in your reading experience.
Nope. Ryomen Sukuna has no basis in reality. It's a product of the creative minds of the writers and illustrators who designed a captivating fictional character for the enjoyment of the audience.