Naruto's relationships could also change. His friends might be in awe of his new ability at first. But as time goes on, they'd work together to incorporate the Crystal Release into their team strategies. He could also face jealousy from some other shinobi who don't have such a rare power. This would force Naruto to handle different social situations, further developing his character as he tries to maintain harmony while still using his new ability to protect those he cares about.
Naruto's character would likely become more versatile. The Gunbai would force him to think differently about combat, as it's a different weapon compared to his kunai or shuriken. This would make him more strategic and less reliant on his brute force.
Naruto's character development would take a whole new turn. As a kid with the Rinnegan, he'd be seen as a prodigy. This would attract different kinds of attention, both positive and negative. He might develop a more complex view of the ninja world earlier. He would no longer be just the underdog trying to prove himself. Instead, he'd be a force to be reckoned with. His relationships with Sasuke and Sakura would also be affected. He might become more of a leader figure among them, guiding them with his newfound power, and his journey to become Hokage would have a different flavor as he would already have such a significant power advantage.
His character would likely become more complex. He might initially feel a sense of isolation as he realizes he's different now with the virus. But he could also grow more determined to control the virus and use it for good. For instance, he may see it as a new kind of power he has to master, just like his chakra.
Naruto's confidence would likely increase significantly. Having such a powerful and unique ability would make him feel more capable of protecting his village and friends. He might become a bit more reserved at first, as he tries to understand and master the new power, but eventually, he would use it to be more assertive in battles and in diplomatic situations as well, knowing he has an ace up his sleeve.
Naruto would likely become more introspective. The Rinne Sharingan is a very powerful and somewhat mysterious ability. Having it would force Naruto to understand more about the deeper aspects of chakra and the ninja world. He might become a bit more cautious as he realizes the great power he holds and the potential for it to be misused.
He would become more stealthy. Shisui's Sharingan could give Naruto an edge in sneaking up on enemies.
He'd become more mature. Knowing Minato's experiences would make him see the ninja world from a different perspective.
Naruto's character would develop in multiple ways if he got the Rinnegan. Firstly, he would become more cautious. The Rinnegan is a powerful and dangerous ability, and one wrong move could have disastrous consequences. So he would think twice before acting. Secondly, he would gain a new sense of purpose. He might see himself as a guardian of a greater balance in the ninja world, not just the Hidden Leaf. His leadership skills would also be enhanced. He could use the Rinnegan to analyze battle situations more accurately and lead his comrades more effectively. Additionally, his view of the ninja world's history would expand, as the Rinnegan has connections to ancient powers and events. This would make him more of a sage - like figure, guiding the younger generation with his new - found wisdom and power.
His sense of self - identity might be shaken. Ichigo has always been defined by his role as a Soul Reaper and his own unique powers in the Bleach universe. Adding the Sharingan would introduce a foreign element. He would have to figure out how this new power fits into his existing power set and his moral code. He might question whether he's still the same Ichigo or if this new power is changing him into someone he doesn't want to be. This internal struggle could lead to significant character growth as he grapples with his new identity.
Ichigo's character would become more complex. He has always been a straightforward fighter, but with Kyoka Suigetsu, he'd have to deal with deception. He might become more cautious in his battles, always doubting what he sees. His relationships with his friends could also be strained as they might not trust him with such a deceptive power. He would have to constantly prove that he's still the same Ichigo and that he won't use the power for evil.