In this kind of fanfiction, Naruto's character would be put in a really tough situation. His sense of loyalty would be tested to the extreme. If he's betrayed, he might become a much darker character. He could start using his powers in ways he never would have in his original Naruto universe. He might target Sora and his friends, seeing them as the cause of his misfortune. And the whole story could be about how Naruto tries to find his way back to his true self or if he's too far gone, how the Kingdom Hearts world has to deal with this new, powerful, and vengeful threat.
In a 'Naruto betrayed Kingdom Hearts' fanfiction, Naruto could be betrayed first in the Kingdom Hearts world which then causes him to lash out. He may feel that he has been used or not given the respect he deserves. His reaction might be to join forces with the villains of the Kingdom Hearts universe out of spite. He could start causing chaos, using his shadow clones to create diversions and his Rasengan to attack key locations in the Kingdom Hearts realm.
Well, in such a fanfiction, Naruto might be made to turn against the principles or characters in the Kingdom Hearts world. Maybe he's tricked into believing false things about his friends there. For example, if there are some dark forces at play, they could manipulate Naruto into thinking his newfound allies are actually his enemies. This could lead to some epic battles where Naruto uses his ninja skills against the Keyblade wielders.
If RWBY watches Kingdom Hearts fanfiction, it could lead to some interesting discussions among them. They could compare their own experiences in Remnant to the events in the fanfic. Maybe they'd even start to wonder if there are similar forces at work in their world. They might also pick up on new ideas for fighting techniques or strategies, as Kingdom Hearts often has unique battle concepts. Additionally, they could be introduced to new character archetypes that might influence how they view their own allies and enemies.
It could be Xehanort. He's a powerful and devious character in Kingdom Hearts. If he sensed Naruto's power and saw him as a threat, he might engineer a situation where Naruto is made to feel betrayed. Xehanort could manipulate the events and the people around Naruto to make it seem like his new friends in the Kingdom Hearts world are against him, all so that he can either eliminate Naruto or turn him to his side.
It's a really strange concept. Maybe Kingdom Hearts would gain some new and wacky ideas from the Harry Potter fanfiction world. It could be influenced by the magic and adventures in those stories and perhaps incorporate some of the unique elements into its own universe in a very unexpected way.
In a fanfiction scenario where Xemnas kidnaps Kairi, it could lead to a great adventure for Sora and his friends to rescue her. Sora would likely be filled with determination and rage, fueling his journey to face Xemnas once again. The story could explore the dark realm where Kairi is held captive, perhaps with new and dangerous Heartless created by Xemnas.
In such a fanfiction, Naruto might be betrayed by his new allies in the DxD world due to misunderstandings. For example, his powerful jutsu could be misconstrued as a threat. His loyalty to his own ninja way might clash with the values of the DxD characters, leading to a rift.
In this kind of fanfiction, Naruto might face a lot of challenges. Maybe Rias, for some reason, turns against Naruto. Naruto could find himself isolated and having to fight against Rias' forces. He would probably rely on his ninja skills and his strong will to survive.
It would be chaos! Sora would likely be the first to try and figure out what was going on. He'd be both excited and a bit worried that these new versions of events were messing with the real story.
If Sora goes back in time in fanfiction, it could be a chance for him to gain new powers or knowledge. He might meet his younger self and teach him things, or he could discover secrets about the Keyblade that were lost over time. This could make him even stronger in his own time and better equipped to face the Heartless and other enemies.
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.
Well, if Naruto is godlike and betrayed by everyone in a fanfic, it could start with the villagers' fear of his newfound power. They might think he's a threat and turn on him. Naruto, being so powerful, could initially be in disbelief. But as the betrayal sinks in, he might decide to leave the Hidden Leaf. He could then wander the world, trying to figure out his place in it while also being cautious of those who might want to take advantage of his power or finish him off.