Well, in this fanfiction scenario where Naruto is Deidara's brother, it would be a huge shock to both the characters and the readers. Naruto has always been seen as a pure - hearted hero of the Leaf, and Deidara was a dangerous member of the Akatsuki. Naruto's character development could take a different turn. Maybe he would have a different view on the Akatsuki and their motives. He might even try to convert Deidara to the side of good, which would be a very interesting story arc. And his friends in the Leaf might be very suspicious of him at first, but Naruto would surely prove his loyalty in his own unique way.
In this fanfiction, perhaps it's a story of redemption for Deidara. Naruto, as his brother, could be the one to show him a different path. They might go on adventures together, facing various challenges that test their relationship. It could also explore how their powers might be related or different, given their connection as brothers.
In this scenario, Naruto being Shisui's brother would mean he might have grown up with a different kind of training. Shisui was highly skilled in the ways of the ninja. Naruto could have learned some of his stealth and combat techniques at an earlier age. This would make him an even more formidable opponent. Moreover, it could have an impact on the Akatsuki's plans. They were after the Sharingan, and if Naruto was related to Shisui, they might target him differently. It could also change the way the village of Konoha views Naruto. He would have a stronger connection to the Uchiha, which could either make them more suspicious of him or more protective, depending on how the story unfolds.
One possible plot development could be that they initially fight against each other as enemies, not knowing their relation. Then, through some kind of accident or revelation, they find out they are brothers. This could lead to a lot of internal conflict for both of them, especially for Deidara who has been on the 'wrong side' in the eyes of Konoha. Another development could be that there is a third party who knows about their relation and tries to use it for their own gain, forcing Naruto and Deidara to work together to overcome this threat.
If Naruto were Sakura's twin brother, the story would be very different. Naruto would have someone in his family from the start, which would have affected his personality. He might not be as eager to seek attention and approval as he was in the original story. In terms of their ninja training, they could have learned from each other. Sakura might have taught Naruto some of her book smarts when it comes to ninjutsu theory, and Naruto could have shown Sakura some of his more unorthodox but effective combat techniques. Their relationship with Kakashi as their sensei would also change, as Kakashi would have to deal with the unique bond between the two siblings.
Well, if Naruto was Minato's younger brother in fanfiction, it would completely change the relationship dynamics. For one, Naruto might not be the outcast he was in the original story. He could have had some of Minato's prestige rubbed off on him. Also, his training might have been different. Instead of having to struggle so much on his own, he could have had Minato's direct guidance from the start. And the whole mystery around his parents would be non - existent, which was a big part of the original story's intrigue.
The Naruto storyline would be altered drastically. Firstly, Naruto's training would change. Instead of focusing on chakra control for Rasengan and Sage Mode, he'd be learning to mold explosive clay. His relationships might also change. His friends might be a bit more cautious around him since his new abilities are more dangerous. In battles, Naruto could target enemy bases or large groups of opponents with his new - found Deidara - like powers. He could even use the element of surprise more effectively, like when Deidara attacked Gaara. This would make Naruto a more versatile fighter and could potentially change the balance of power in the Naruto universe.
I'm not sure of a specific 'naruto deidara is naruto's brother' fanfiction, but generally in such a concept, the fanfic could start by exploring how they were separated at a young age, perhaps due to some sort of conflict between the Hidden Leaf and Iwagakure. Then as the story progresses, they could discover their relation in a very dramatic way. This could then lead to them having to choose between their existing loyalties (Deidara to Akatsuki and Naruto to Konoha) and their new - found brotherhood.
Well, if Naruto had Deidara's bloodline, his explosive - related abilities would likely be enhanced. He might be able to create explosive clay like Deidara. His combat style could shift towards more long - range attacks with these explosive elements, adding a new dimension to his already diverse set of skills.
In this fanfiction, it could also be that Naruto discovers a connection between Deidara and some ancient ninja art or prophecy. This discovery could lead him on a journey to uncover more about his supposed father's past. Along the way, he might encounter characters who knew Deidara and learn different aspects of his personality that were not known before. He could then use this knowledge to better understand himself and his place in the ninja world.
In this fanfiction, perhaps the story focuses on how Deidara's explosive and creative nature influences Naruto. Deidara could be showing Naruto how to think outside the box in battles. Also, there could be a lot of character development for Naruto as he adapts to Deidara's unorthodox ways. For example, Naruto might start to incorporate some of Deidara's artistic flair into his own jutsu, creating a whole new style of fighting that surprises his friends and enemies alike.