Well, if Sasuke dies in this fanfiction set in the Wave arc, Naruto would likely become more determined to avenge him. He might also grow more solemn and focused on his ninja training, realizing the fragility of life. His view of the world could shift from being a bit more carefree to a darker, more serious one as he grapples with the loss of his friend and rival.
Sasuke's death would be a huge blow to Naruto. In the story, Naruto has always seen Sasuke as both a friend and a rival. His death could make Naruto question his own strength and purpose. Naruto might become more withdrawn at first, blaming himself for not being able to protect Sasuke. But eventually, it could fuel his growth. He could strive to become stronger not just for himself but also to honor Sasuke's memory. He might also develop a more empathetic side towards others who have lost loved ones.
Well, Naruto's death would likely shatter Sasuke. He has always had Naruto as a sort of anchor, whether he admitted it or not. His whole life has been intertwined with Naruto's. Naruto's death might make Sasuke question his entire purpose. He could initially be filled with rage and a thirst for revenge, thinking that he could have prevented it. This could lead him down a darker path at first. But eventually, it might also make him realize the importance of Naruto's ideals and he could strive to carry them on in Naruto's memory.
One possible reason could be that he overestimated his abilities during a battle in the Wave arc. Maybe he took on an enemy that was much stronger than he thought and got fatally injured. Another reason could be that he sacrificed himself to save Naruto or someone else. It's also possible that there was some sort of betrayal within the group they were with, and Sasuke was caught off - guard and killed.
The team dynamic would be completely shattered. Sakura would be devastated as Sasuke was someone she had strong feelings for. Kakashi too would feel responsible for not being able to protect Sasuke. This could lead to the team splitting up or at least going through a long period of internal turmoil and lack of cooperation. And it might also change the way the village views their team, perhaps with disappointment or a sense of loss.
Naruto might become more determined. With Sakura's death, he could see the harsh reality of the ninja world more clearly. It might make him more resolved to bring peace, as he has now lost someone important. He may also become more protective of his remaining friends, vowing not to let any more harm come to them.
In this kind of fanfiction, Sasuke could die from a sneak attack. He might be so focused on his main target during the Wave mission that he doesn't notice another hidden threat. And this hidden enemy could strike him when he least expects it, leading to his death. For example, an assassin could be hired to specifically target Sasuke and use some sort of poison or a deadly jutsu that he can't defend against in time.
Sasuke might be in shock at first. He can't believe that Naruto is dying in his arms. He may feel a great sense of guilt, thinking that he could have done more to prevent it.
It could make Naruto more introspective. He might question his own worthiness of Hinata's sacrifice. This could lead to him delving deeper into his own beliefs and values. He may also become more empathetic towards others who have lost loved ones, as he now has first - hand experience of that kind of pain. He would grow in maturity, realizing that his actions have consequences not just for himself but for those around him who care about him deeply.
In this fanfiction, the act of Sasuke kissing Naruto's neck might be a turning point. It could make Naruto more aware of Sasuke's emotions towards him. Maybe Naruto has always been a bit oblivious to Sasuke's deeper feelings. This moment forces him to confront and evaluate their relationship. For Sasuke, it could be a way of finally expressing himself after holding back for so long. This exchange then paves the way for them to communicate more openly about their relationship and move towards a closer, more trusting connection.
Sasuke's character often develops in terms of his loyalty. By saving Naruto, he shows that his loyalty to their friendship is growing stronger. He may start to question his previous lone - wolf attitude.
Naruto might protect Sasuke by using his physical strength. He's got those powerful jutsus like the Rasengan. If any enemy comes near Sasuke, Naruto can just blast them away with his attacks.