Sasuke would be deeply affected as well. He has a complex relationship with Sakura. He might withdraw into himself even more. He would probably be very angry, but his anger would be more of a cold, brooding kind. He would likely start his own investigation into her death, and depending on the circumstances, might take revenge in his own way, which could be quite brutal.
Both Naruto and Sasuke would also be reminded of their own mortality. Sakura's death could be a turning point for them. They might re - evaluate their lives and their goals. Naruto could become more determined to bring peace to the ninja world so that no more friends would have to die in vain. Sasuke might become more involved in the affairs of the village he once shunned, seeing the importance of protecting those around him after losing Sakura.
Naruto would be devastated. He's always been one to value his friends deeply. He might initially go into denial and then be filled with rage, vowing to find out who or what was responsible for her death and seek justice. He would also likely carry a great deal of guilt, thinking that he should have been able to prevent it.
Sakura would be devastated. She would probably blame herself for Naruto's death since he died protecting her. She might go into a state of deep depression at first, withdrawing from everyone.
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.
Naruto might also try to remember Sakura in a positive way. He would cherish the memories they had together. He could start initiatives in the village in her name, like promoting medical ninja training more, since Sakura was a great medical ninja. He would slowly turn his grief into a force for good in the village.
She could be heartbroken. Sakura has always loved Sasuke deeply, so his leaving for Naruto would be a huge blow to her. She might initially be in denial, not believing that Sasuke would choose Naruto over her.
He may also choose to defend himself without really fighting back. Naruto values Sakura as a friend and teammate, so he would be reluctant to harm her. He might just try to dodge her attacks and keep talking to her, hoping to snap her out of it.
Naruto might initially be in denial. He's so used to having Sakura around and believing that they have a future together. So when she leaves for Sasuke, he might think it's just a temporary thing or that she's been influenced by something or someone. But as time passes and he realizes it's real, he would be deeply hurt. He might also start to question his own self - worth, thinking that he wasn't good enough for Sakura. And he might even try to win her back at first, but then slowly come to accept the situation and focus on his other responsibilities like being a ninja and protecting the village.
Sakura would likely be devastated. Naruto has been her friend and teammate for a long time. His death would leave a huge void in her life, and she'd probably go through a long period of mourning.
Naruto would be devastated. Sasuke is his closest friend and rival. He would likely go into a state of deep mourning at first. He might isolate himself for a while, just trying to come to terms with the loss.
Well, Naruto might be furious. He's always been protective of Sakura. He'd probably drop everything he's doing and go after Sasuke to rescue Sakura. Naruto has a strong sense of justice and loyalty, especially towards his friends. And Sakura is one of his closest friends, so he won't stand by and let her be in danger.
One of the most popular themes is redemption. Sasuke has made many mistakes in his past, and fanfictions often explore how Sakura can be a part of his journey towards redemption. For example, she might help him face his inner demons and find peace within himself.