Sakura would be completely devastated. She's been in love with Sasuke for so long and has a deep bond with Naruto too. She might go into a deep depression and lose her will to be a ninja for a while.
Kakashi would feel a deep sense of loss. He was Naruto's mentor and had a connection with Sasuke as well. He might become more withdrawn and question his own teachings, wondering if he could have done something to prevent their deaths.
The village as a whole would be in mourning. Naruto was seen as a hero and Sasuke was also an important figure. There would be a lot of sadness, but also a sense of unity as they come together to remember the two and figure out how to move forward without them. People might also start to tell stories about their great deeds, turning them into legends.
Sakura would be devastated. She has always had deep feelings for Sasuke. She might initially be angry with Naruto, thinking that there could have been another way. But later, she might understand Naruto's difficult decision when she realizes the threat Sasuke posed.
The Hidden Leaf villagers would be shocked. They see Akatsuki as the enemy, so they would think Naruto and Sasuke have betrayed them. Kakashi would probably be very concerned and try to find out their reasons. Sakura would be heartbroken and might even try to go after them to bring them back. As for the Akatsuki members themselves, some might be suspicious of Naruto and Sasuke's motives at first, while others might see it as an opportunity to use their power for Akatsuki's goals.
Sakura would be devastated. She has deep feelings for both Naruto and Sasuke. She would probably be angry at Sasuke for killing Naruto and at the same time feel guilty for not being able to stop it. She might even try to take revenge on Sasuke.
Sasuke would be deeply affected. He and Naruto had a complex relationship. He might feel a sense of regret for all the times he had pushed Naruto away. His reaction could range from anger at the situation to a new - found respect for Naruto's sacrifice.
Sakura would be devastated. She has deep feelings for both Naruto and Sasuke. She might turn against Sasuke completely and try to take revenge herself. Kakashi would be in shock. He has mentored both and would likely feel like he failed in some way. As for the other ninja from the Hidden Leaf, they would be angry and mournful at the loss of their hero Naruto.
Sasuke would probably be one of the most affected. He might feel a mix of guilt for not being able to prevent Naruto's death in the first place and relief at his revival. Sakura would be overjoyed, and she'd likely be the first to rush to Naruto's side to check if he's really okay. Kakashi, on the other hand, would be more reserved in his reaction, but still happy to see Naruto back.
Naruto would be extremely devastated. He sees Kakashi as a mentor and father figure. He might go into a period of deep depression at first, but then turn his grief into motivation to become stronger. Sakura would also be very sad and might focus more on her medical skills, vowing to save more lives in Kakashi's memory. Sasuke might have a more internal reaction, feeling guilty if Kakashi died protecting him, and it could further fuel his own goals, whatever they may be at that time.
Sasuke would likely be very conflicted. He has a deep bond with Naruto, and he would not want to fight him, but he also has loyalty to Konoha. He might try to reason with Naruto first before taking any aggressive action.
The village elders would also be concerned. They might start to think about the future of the village without Naruto. Some might even start looking for a temporary replacement for him as Hokage, which could cause some internal conflict in the village as not everyone would agree on who should take over.
In some fanfictions, there are special abilities or bonds that enhance their understanding. Maybe a magical connection that allows them to feel each other's emotions. This makes it easier for them to know what the other is thinking or feeling at any given moment. So, when one is in danger or has a strong emotion, the other can sense it and respond accordingly, deepening their understanding of one another.