Naruto could be very determined to change the future he saw. For instance, if he saw a future where his friends were in danger, he would immediately start planning how to prevent it. He would probably gather his friends and tell them what he saw, and together they would come up with a plan to avert the bad future. He is not the type to just sit and accept a bad future.
He might be shocked at first. Just imagine seeing things that haven't happened yet. It's quite a mind - blowing experience.
In some fanfictions, Naruto's reaction to seeing the future could be a bit more complex. He might initially not believe what he saw. After all, it's something so out of the ordinary. But as he starts to notice small signs that match what he saw in the future, he gradually realizes it's real. Then he would start to feel a sense of responsibility, especially if the future involved the safety of the village or his loved ones. He would then use all his skills and powers, and also his influence on others, to try and change the course of events.
At first, he may be in disbelief. But as he starts to understand what he's seeing, he could become solemn. He realizes the weight of the future and the responsibility he may have to shape it in a positive way. He might also feel a bit of fear, especially if he sees the loss of his friends or loved ones. But overall, his Gryffindor courage would likely kick in, and he'd start to think about how to face whatever the future holds.
He could be shocked at the brutality. Maybe he'll be stunned into silence at first, just taking in all the chaos and destruction.
He may laugh out loud at the funny parts. Some fanfictions are full of humorous situations and dialogues that can really tickle his funny bone.
Naruto might have a mixed reaction. He could laugh at the funny parts of the fanfiction. However, if the fanfiction misrepresents his friends or his village in a negative way, he might get angry. He's very protective of those he cares about. He may also be intrigued by the different versions of himself that are presented in the fanfiction, and might even start to think about how he can grow in those new directions.
Well, Howard Stark might have a range of reactions. He could be in awe of the advancements, or he might feel a bit left behind. Maybe he'd also have some fatherly pride and a desire to have been more involved.
In some cases, Naruto could be deeply hurt and withdraw from Hinata. He might question their relationship and whether he misjudged her all along. If the hurt is physical, he may also be more cautious around her in future interactions. For example, if she accidentally used a strong jutsu on him during training, he might be hesitant to train with her again without proper precautions.
He quickly uses his observational skills. Naruto has always been good at noticing things around him. So he'd start by looking at how people in the future live, move, and interact.
Naruto would be excited and ready to face whatever comes. He's always been positive and believing in his ability to change things. So, he'd see it as a challenge to make the future better.
At first, Naruto might be really confused. He's used to thinking of his friends as his support system, so when they turn on him, he doesn't understand why. He'll probably try to talk to them, to ask what he did wrong. If they don't listen, he could become really sad and withdrawn. Maybe he'll start training even harder, using the pain of being rejected by his friends as motivation to become stronger.
He probably gets very worried. Kakashi is Naruto's teacher and mentor, so he'd likely be immediately concerned and rush to Naruto's side to assess the situation.