Their relationship could develop as they start to respect each other's skills more. As they train, they see the hard work and determination in each other, which makes them put aside their past grudges. For example, when Naruto manages to dodge one of Sasuke's powerful attacks, Sasuke realizes that Naruto has truly become stronger. This makes him more open to working with Naruto rather than against him.
A really interesting scenario could be that Naruto and Sasuke are training in a place where there is a time - dilation effect. They end up spending what seems like months in the training area, but in the outside world, only a few days have passed. During this extended training time, they not only improve their combat skills but also their relationship. They share stories from their past that they never had the chance to before, and by the time they come out, they are both much stronger and closer as friends and comrades.
One possible plot could be that Naruto, having become much stronger and more experienced over the years, takes Sasuke under his wing to help him master new jutsu. Maybe Naruto teaches Sasuke some of his unique Rasengan variations, and they train in a secluded area away from the village. Along the way, they also have heart - to - heart conversations about their past and how they can better protect the village together.
In the fanfiction, they could be training under a strict master. This master gives them tasks that require them to combine their abilities. For instance, they have to work together to break through a powerful chakra barrier. Naruto's brute strength and Sasuke's precise chakra control are both needed. At first, they struggle because of their differences, but as they communicate more during the training, they start to synchronize their efforts and finally break through the barrier, growing closer as comrades in the process.
The training could strengthen their bond. They have to work together to teach the young one, so they need to communicate better. For example, Naruto might suggest a more fun - filled training method, and Sasuke might initially oppose it but then see the value in it. This back - and - forth can make them understand each other's perspectives more, just like in their own growth as friends.
Perhaps he's been influenced by someone who gives him bad advice. For example, if someone tells him that natural talent is enough and training is overrated. Also, he could be dealing with some personal problems, like a conflict within his family or among his friends that takes up all his time and mental energy, causing him to neglect training.
In this fanfiction, Hokage Naruto might take Naruto to a special training ground. There, he could teach Naruto some of his own unique jutsu combinations. For example, he could show Naruto how to combine the Rasengan with his Sage Mode more effectively. This would give Naruto a huge power boost and also make him more confident in battles against tougher opponents.
Yes, there might be such fanfics out there. In the Naruto fandom, with a large number of fans creating various types of stories, it's possible that some would write a story where Naruto destroys Sasuke in a way that could be seen as Sasuke - bashing. However, these kinds of fanfics may not be in line with the overall spirit of the original work which focuses on their complex relationship and growth.
It could be due to the current situation in the village. There might be threats that required Naruto to stay. Tsunade, as the Hokage, had to consider the overall safety and stability of the village. So, she denied Naruto's request for the training trip to ensure he was available in case of any emergency.
Well, in the 3 - year training fanfiction, Naruto could also have some intense mental growth. He might learn more about the history of his clan and the ninja world from Jiraiya. This knowledge would not only make him a better ninja but also shape his understanding of his place in the world and his responsibilities.