Naruto might also develop a different set of values. Instead of the traditional ninja values that he learned in the original story, he could create his own set based on his experiences of being alone and having this powerful ability. He could become more of a loner, relying only on his own strength and the power of the Rinnegan. And his attitude towards the village might change. He might not be as eager to protect it at first, feeling that since his parents didn't care about him, why should he care about the village they were from.
Well, for starters, his power progression would be completely different. Without parental support, he'd have to figure out the Rinnegan's abilities all by himself. Maybe he'd accidentally unlock some dangerous powers early on because he didn't have anyone to guide him. His emotional state would also be a mess. He'd probably be angry at his parents for neglecting him and use that anger as fuel to train harder.
In fanfiction, Naruto having the Rinnegan and being neglected by parents can lead to some really interesting character development. It could make him more self - reliant and distrustful at first. He might have to learn to harness the power of the Rinnegan on his own, without any parental guidance. This could result in him making some mistakes along the way but also growing stronger in unique ways.
If Naruto had both in fanfiction, he'd be insanely powerful. His combat abilities would skyrocket. He could use the Sharingan to quickly analyze his opponents' moves and the Rinnegan to counter with powerful six - paths techniques. For example, he could use the Sharingan to predict an enemy's attack and then use the Rinnegan's Deva Path to repel it with ease.
In the wider ninja world, his relationship with other villages would change. Some villages might see him as an even greater threat now that he has the Rinnegan, and might try to form alliances against him. However, Naruto being Naruto, he would use his new power to show that he still has the same kind - hearted goals. He would try to use the Rinnegan to bring about peace even more strongly, and over time, win over those who were initially suspicious.
He might also become more isolated at first. The power of the Rinnegan could make him feel different from his friends. He may think that they can't understand what he's going through with this new power, so he could withdraw a bit until he learns to balance his new abilities with his old relationships.
If Naruto got the Rinnegan, he might become more cautious. The power of the Rinnegan is so great that he would realize he needs to be more careful with it. He wouldn't be as brash as before.
The story would be a whole new ballgame. Naruto's training would have taken a different route. Instead of focusing on basic chakra control and simple jutsu at first, he might have delved straight into the more advanced abilities that the Rinnegan offers. His battles would be less about brute strength and more about the strategic use of the Rinnegan's powers, like the ability to absorb and manipulate chakra in ways that no one in the village had seen before. This would have also affected how the village elders and the Hokage treated him, perhaps with more caution and respect due to his innate and potentially dangerous power.
If Naruto gained Nagato's Rinnegan, it would completely change the power dynamics in the Naruto universe. Naruto already has his own powerful abilities like the Nine - Tails chakra. With the Rinnegan, he could potentially master all six paths techniques with ease. His combat capabilities would skyrocket, and he might be able to defeat enemies much faster. For example, he could use the Deva Path to manipulate gravity, which would be a huge advantage in battles against strong opponents.
His character would have a darker edge. The vampire nature could bring out a more primal and possessive side. And the Rinnegan would give him new levels of power and knowledge. He might start to question his old values as he realizes the potential of his new powers. He could become more solitary, training alone to master his combined abilities rather than relying on his friends like he used to.
If Naruto had 3 siblings, his loneliness as a child would have been much less. He would have had a support system from the start. His siblings could have helped him train, so he might have become stronger faster. For example, they could have sparred with him regularly. Also, in the story, when facing challenges like the Akatsuki, his siblings could have joined forces with him, making the battles more balanced and potentially having different outcomes.
Their relationship would likely become more complex. With the Rinnegan involved, they might have to rely on each other more for understanding its powers. They could become more protective of each other, knowing the power and the danger it brings.