Sasuke would be very cautious. He has a history with Madara and would be on guard. He might not trust Madara even if Naruto believes in him.
The other ninja villages would be on high alert. Madara was a major threat before, and his revival would be a cause for concern. They might see Naruto's association with him as a dangerous move. However, some of the younger ninjas might be in awe of Madara's power and look up to Naruto for being able to handle the situation.
The Akatsuki members, if any are still around, would have mixed reactions. Some might see Madara's revival as an opportunity to further their own goals, while others might be worried that Madara would take over the organization again. And for Naruto's friends like Shikamaru, they would be worried about Naruto getting in over his head but also trust that he has a plan to deal with Madara.
It would depend on the writer's intention. If the focus is on Naruto's growth, he could start exploring new jutsu or forms of chakra control. Since he was revived by Madara, there might be some dark elements associated with his revival that he has to overcome. Maybe he has to fight off some sort of curse that came with the revival process. And he would have to do this while still trying to protect the people he cares about.
The other Konoha ninjas would be quite shocked. The Hokage, whoever it is at that time, would see Naruto's change as a potential threat to the village's stability. They would likely keep a close eye on him and try to figure out what caused this transformation. Meanwhile, the younger generation of ninjas who looked up to Naruto would be confused and disappointed. They expected Naruto to be their role model of a kind - hearted and positive ninja, not someone acting like the feared Madara.
Naruto would be extremely enraged. He would vow to rescue Sakura no matter what. He would immediately start gathering his friends and form a rescue team. Sasuke, on the other hand, might initially seem more reserved but would also be determined to get Sakura back. He would use his Sharingan skills to track Madara.
Sasuke might be a bit taken aback at first. He's used to Naruto's normal look, and this change could make Sasuke see Naruto in a new light, perhaps as a more formidable opponent or an even stranger ally. Sakura would probably be shocked too. She might tease Naruto about it at first but then grow to accept it. Kakashi would likely raise an eyebrow and make a comment about how Naruto is always full of surprises with his new look.
Harry would be on guard at first. He has faced many dark threats in his life, and Madara would seem like another one. But as he gets to know Madara better, he might see some similarities in their struggles. Dumbledore would likely be very interested in Madara. He would try to understand Madara's motives and see if he could be an ally or a threat to the wizarding world. Dumbledore would be cautious but also open - minded in dealing with this new and strange character.
Sasuke would probably be one of the most affected. He might feel a mix of guilt for not being able to prevent Naruto's death in the first place and relief at his revival. Sakura would be overjoyed, and she'd likely be the first to rush to Naruto's side to check if he's really okay. Kakashi, on the other hand, would be more reserved in his reaction, but still happy to see Naruto back.
Well, it could involve Madara having a new purpose. Maybe he decides to help Naruto against a new, greater threat. Since he was revived, he might have a different perspective on the ninja world now.
If Naruto was an Ajin in a fanfiction, the characters in Naruto would have a mix of reactions. Hinata would be concerned for Naruto's well - being. She might be a bit scared at first because of his new and strange abilities, but still stand by him. The villagers, who have had a rocky relationship with Naruto in the past, might be afraid of him all over again. They could see his Ajin powers as a threat. On the other hand, Naruto's close friends like Shikamaru would try to understand what's going on and help Naruto control his powers if they can.
Sakura might be initially shocked and a bit scared of Robocop's robotic appearance. But once she realizes he's on their side, she would be interested in his technology and might even try to learn from it to improve her medical ninjutsu tools. Naruto, on the other hand, would be super excited. He'd probably want to immediately be friends with Robocop and would be eager to see what kind of cool moves he can do. Kakashi would be more cautious, observing Robocop carefully to assess his capabilities and motives.
Naruto would be thrilled. He loves being the center of attention and seeing all these stories about him would make him feel even more important. He'd probably want to meet the writers and tell them how cool he thinks their ideas are.