He would likely feel a great sense of anger. Naruto has a strong will, and this betrayal would fuel his anger. He might be determined to find out the truth and get revenge on those who wronged him. At the same time, he would also be in deep pain. It's like losing the most important thing in his life. This emotional turmoil could lead to a change in his personality, making him more withdrawn and less optimistic than before.
In such a fanfiction, Naruto might become extremely disillusioned. He could turn to his friends like Sasuke or Sakura for support. He might also start to question his own worth and purpose, leading to a much darker and more complex character arc.
Another aspect could be influenced by external forces. Let's say an evil organization manipulates Naruto's family. They use mind - control or blackmail to make his family act against Naruto. In fanfiction, this can add a layer of drama and tragedy. It makes Naruto's journey even more difficult as he has to not only face external enemies but also deal with the betrayal of his own family.
Naruto's character would go through a major transformation. He'd lose some of his naivete and innocence. Instead, he'd become more cynical, but also more determined. He'd no longer take loyalty for granted and would be more cautious in his relationships. As he overcomes obstacles, he'd develop a new sense of identity that is not tied to his family's expectations.
One idea could be that their own village betrays them. Maybe there's a power - hungry leader who sees Naruto and his sister as threats to their new regime. They could be framed for a crime they didn't commit and then forced to flee the village. In the process, they might have to rely on some unlikely allies they meet on their journey, like a group of outcasts who also have a grudge against the village.
Naruto's power might also be affected. If he was betrayed, he could lose the will to fight or train. He might even start to doubt his own purpose. This could lead to a decline in his abilities, which in turn could put the village at risk if he was its main protector.
His reaction would depend on how the betrayal was presented. If it was a sudden revelation, he would be shocked and devastated. He may start to question his own worth, thinking that if his own parents could betray him, what was wrong with him? He could also become more reckless in his actions, not caring about the consequences as much since he felt like he had already lost the most important thing. This new Naruto could also be more empathetic towards the villains in the story, understanding their feelings of being wronged or betrayed in some way.
He could then feel a deep sense of anger. Naruto has a temper, especially when it comes to those he loves. He might vow to find out the reason for the betrayal and make things right, or if it was truly malicious, seek revenge in his own Naruto - like way, which would involve trying to understand the person's motives even while being angry.
At first, Naruto would likely be shocked. He has always been so loyal to his team, and this sudden betrayal would be a huge blow. He might stand there in disbelief, unable to process what's happening.
Well, one possible plot could be that his family wrongly accuses Harry of using dark magic without proper evidence. They then shun him and spread false rumors about him in the wizarding community, leaving Harry feeling isolated and betrayed.