If Naruto was Deidara's brother, their relationship would be a study in contrasts. Naruto, with his bright and sunny personality, would be the polar opposite of Deidara's brooding and destructive nature. At first, Deidara might resent Naruto for being so different from him and for having a more positive view of the world. But as time passed, Naruto's unwavering belief in the good of people could start to rub off on Deidara. They might have some intense arguments about their different worldviews, but also share some quiet moments where they just understand each other as brothers. And Naruto would always be there to pick Deidara up when he was down, even if Deidara didn't always show his appreciation.
It would be a relationship full of mutual growth. Naruto, with his never - give - up attitude, could inspire Erza to keep pushing forward in the face of adversity. At the same time, Erza's strong - willed and independent nature could make Naruto realize that he doesn't always have to carry the burden alone. They would also have a lot of fun together, with Naruto's sense of humor bringing some light - hearted moments into Erza's often - serious life.
In such a fanfiction, Naruto might develop a very different set of skills. Since Deidara is an artist who uses explosive clay as his medium, Naruto could learn unique ways of combat that combine his natural chakra control with explosive techniques. His personality might also be affected. He could be more impulsive like Deidara at times. However, Naruto's core values of friendship and protecting the village might still remain, but they could be expressed in a different way, perhaps with a more artistic or explosive flair.
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.
The relationship could be one of mutual learning. Naruto could be the more light - hearted one, always trying to get Bruce to loosen up a bit. Bruce, on the other hand, would be the more strategic and calculating brother. They might argue about the best ways to approach problems, with Naruto advocating for a more direct and emotional approach while Bruce prefers a more stealthy and planned - out method. However, their love for each other as brothers would keep them together through thick and thin.
If Naruto was Itachi's twin brother in this fanfiction, Sasuke's relationship with both of them would be extremely complex. Naruto would be Sasuke's family in a different way than just a friend. He might be more protective of Sasuke from the start. And Sasuke would view Naruto not just as a rival to surpass but also as part of his family's mystery. Since Itachi was Sasuke's brother, Naruto being Itachi's twin would put Naruto in a strange position in Sasuke's eyes, perhaps a mix of suspicion and a longing for family connection.
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.
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.
It would likely be a very protective relationship. Harry, being the older brother, would probably use his magic to keep Naruto safe from various threats in the Naruto world. He might teach Naruto some basic magic skills as well, which could give Naruto an edge in his battles.
They would probably have a very close relationship. Twins often have a special bond, so Naruto and Ino would likely be no different. They would support each other in their ninja training and missions. Ino might be a bit bossy towards Naruto, but it would be out of love. Naruto, on the other hand, would be very protective of Ino.
Their relationship could be a bit of a push - and - pull. Naruto would probably be the more open and affectionate one, trying to get Batman to open up more. Batman, on the other hand, might be a bit standoffish at first. But over time, he would come to appreciate Naruto's positive energy. They could have arguments about how to handle villains, with Naruto preferring to try and understand and redeem them, while Batman is more about justice and punishment.