Naruto would be shattered. Given his strong sense of justice and his connection to Hinata, whether it's a romantic or platonic one. He would initially be numbed by the shock. But soon, his emotions would erupt. He could go through different stages, from mourning and self - blame (thinking he could have protected her) to a fierce determination to make things right. His actions would be driven by his love and respect for Hinata, and he would not rest until he has either avenged her or found a way to bring her back, if possible.
His friends would be really happy. Shikamaru would probably be like 'Well, it was bound to happen eventually, Naruto.' and offer some practical advice. Choji might bring over some delicious food for Hinata to help with her pregnancy cravings. Kiba would probably joke around with Naruto about how his life is really changing now.
The other villages might react with a mix of shock and suspicion. They knew Naruto was a powerful force for good in the ninja world. His death could be seen as a sign that something was amiss in Konoha. Some villages might even fear that Konoha was becoming unstable and could pose a threat. Characters like Gaara, who had a special bond with Naruto, would be deeply saddened and might try to find out the real reason behind Naruto's death.
Hinata might be shocked at first. She has always adored Naruto, and this sudden act of aggression from him would leave her stunned and unable to process it immediately.
Well, Sasuke would be furious. Naruto was his rival and also his friend. He would seek vengeance on the mob without a second thought. Shikamaru, on the other hand, would be more calculating. He would try to figure out how such a thing could happen and what the long - term consequences for the village would be.
Naruto would be devastated. He and Sakura have a long - standing relationship, and her death would hit him hard. He might go into a rage, seeking revenge on whoever was responsible. Sasuke, too, would be affected. Even though their relationship was complex, Sakura was still an important part of his life. He could become more withdrawn or more determined to change the world that allowed such a thing to happen.
At first, Naruto would be completely shocked. He has always seen Hinata as a loyal friend and someone who has deep feelings for him. So the idea of her betrayal would be hard to fathom. He might try to deny it at first.
He would be filled with rage. Naruto has a strong sense of justice and the fact that someone took Hinata away from him would fuel his anger. He would vow to find and punish whoever was responsible. He might even become reckless in his pursuit of vengeance, endangering himself and those around him. His friends would have to step in to try and bring him back to his senses.
Naruto would probably be heartbroken. He loves Hinata deeply, so finding out she might have cheated would shatter him.
Hinata would likely be conflicted. On one hand, she still has feelings for Naruto, but on the other hand, she can't tolerate his arrogance. So, she would start by observing him from a distance. As she notices how his arrogance is affecting others, she would gather the courage to approach him. She would tell him how his actions are not in line with the values he once held dear, like friendship and protecting the weak. And she would hope that her words would make him reflect on his behavior.
Naruto, being the energetic and battle - loving guy he is, would likely be on the edge of his seat, eager to see who comes out on top in each death battle. He might be making bets with himself about the outcomes. Hinata, with her gentle nature, would be a bit more subdued. However, she would also be intrigued. She might be more concerned about the safety of the fighters, even though it's just a fanfiction battle. And when a fight gets really intense, she might clutch Naruto's arm without realizing it, while Naruto is too engrossed in the action to notice at first.