In a Naruto - is - Gaara's - older - brother fanfiction, the story could start with Naruto finding out about their relation through some ancient scroll or a prophecy. Naruto would then immediately set out to find Gaara. Once they meet, there could be initial tension as Gaara is used to being alone. But Naruto, with his big - hearted nature, would slowly break down Gaara's walls. He could help Gaara with his sand control by sharing his own experiences with chakra control. They might also face a common enemy that forces them to rely on each other and strengthen their brotherly bond.
If Naruto was the older brother of Hashirama, it could completely rewrite the history of the ninja world. Naruto's influence could prevent some of the early tragedies that occurred in the Senju - Uchiha conflict. He might be able to use his charisma and leadership skills to bring the two clans together more smoothly. This would lead to a more stable and peaceful foundation for the Hidden Leaf, and perhaps the entire ninja world would develop differently without the long - standing animosity between the two powerful clans.
It could be full of action. Naruto would bring his ninja skills to Issei's world. He might train Issei in combat, much like he trained with Sasuke and others. Their relationship could also be full of brotherly banter and support.
One possible plot could be Naruto protecting Serena from various threats in their world. Since Naruto is known for his determination and strength, he would use his ninja skills to keep Serena safe. Maybe they live in a world where both ninja and other magical elements exist, and Serena has some special power that makes her a target, and Naruto is constantly on guard.
In this fanfiction, the plot could center around Naruto's past as an orphan and how it relates to Sirzechs' own experiences. They could bond over their struggles and use their combined powers to bring peace to both their realms. Naruto could introduce concepts like chakra to the Underworld, while Sirzechs could teach Naruto about the politics and magic of his world. Their brotherly relationship would be a key factor in uniting different factions within both worlds.
The plot could involve Naruto and Azula discovering their relation later in life. Naruto, being from a different world, would have to adapt to the Fire Nation's culture. Azula might initially be hostile towards Naruto, seeing him as a threat to her power. However, as they interact more, Naruto's unwavering belief in people's goodness starts to chip away at Azula's cold exterior.
Well, it would be a really wild concept. Naruto's ninja world and Vegeta's Saiyan heritage are so different. Maybe Naruto would teach Vegeta some ninja skills like stealth and using chakra in unique ways. And Vegeta might introduce Naruto to Saiyan combat techniques. It could be a story full of clashes between their different values and powers, but also of them learning from each other.
One possible plot could be that they are on a mission to protect a small village from a powerful and mysterious enemy. Gaara uses his sand powers for defense, Naruto with his Rasengan for offense, and Sasuke with his Sharingan to analyze the enemy's moves. Along the way, they face internal conflicts as their different personalities clash but eventually learn to work together better.
It could work if there was a shared backstory created for them. Perhaps they both have a common ancestor or some ancient power that links them. Naruto's strong sense of loyalty and protection could be extended to Natsu as his younger brother. He could teach Natsu some of his ninja values like never giving up and the importance of teamwork. Natsu, in turn, could show Naruto the more carefree and adventurous side of the Fairy Tail world.
The plot could start with Naruto's arrival in the Fairy Tail world. As Laxus' older brother, he would immediately take on a protective role. He could use his rasengan and other jutsu to fight off enemies that threaten Laxus or the guild. Naruto might also try to bridge the gap between the two different power systems - chakra and magic. Along the way, there could be a lot of character development for both Naruto and Laxus. Laxus could learn about Naruto's past and the struggles he had in his own world, which would inspire him to be a better mage. And Naruto would adapt to the Fairy Tail world, using his skills to help the guild grow and protect it from internal and external threats.
A fanfiction with Naruto as Daenerys' brother could have a very interesting plot. Since Naruto grew up without his parents and Daenerys also had a difficult childhood, they could bond over their shared experiences. Naruto could bring his unique sense of humor to the rather serious world of Westeros. His ability to make friends easily might also help Daenerys form more alliances. In terms of battles, Naruto's Rasengan could be used against the White Walkers if the story took that turn. And his relationship with Daenerys could be a complex mix of brotherly love, mutual respect, and a shared goal of bringing peace and justice to their world, whether it's the ninja world or Westeros.