The world would be in shock. The media would be filled with reports of his death. Civilians who had always seen him as a symbol of safety would feel vulnerable. There would be mass mourning in the cities he had protected.
In many fanfics, the Bat Family is often devastated. Bruce might be filled with guilt, blaming himself for not being able to protect Jason. Dick could be angry and determined to find out who was responsible. Tim might feel a sense of loss and also a strange connection to Jason, as he took on the Robin mantle after him.
Sakura would be devastated. She has known Naruto for a long time and has seen him grow from a loud - mouthed kid to a great ninja. His death would make her question everything. She might become more withdrawn and serious. Hinata would be heartbroken. She had deep feelings for Naruto. She might even lose her will to fight for a while.
Well, some characters' reactions can be really complex. For example, Dumbledore's portrait might show a solemn look, as if he knew this was an inevitable outcome. The students at Hogwarts would be in a state of shock. Those who were in Slytherin house might feel a sense of loss for their head of house, even if they didn't always understand him. And Neville, he might see Snape's death as a tragic end to a misunderstood hero.
At the start, Naruto might be in shock. He can't believe that his own family would do such a thing. After the initial shock wears off, he would probably be determined to show them that they made a mistake. He would go on adventures, learn new skills, and meet new people. Through these experiences, he would become more independent and self - reliant. And when the time is right, he might try to confront his family, not in a vengeful way, but to show them that he has changed and that their banishment was unjust.