A really interesting scenario could be that the other villagers start to notice some strange things going on at Sasuke's place. They suspect something is up but don't know exactly what. Naruto and Sasuke then have to be really careful to keep their living arrangement a secret while also dealing with the close - knit community's curiosity. This adds a layer of secrecy and tension to the story.
One possible plot could be that Naruto wants to keep an eye on Sasuke after he returns to the village. He secretly moves in to make sure Sasuke is truly back for good and to support him in his reintegration. Naruto might also hope to rekindle their old friendship in this close - quarters situation.
One possible scenario could be that Naruto snaps at Sasuke over his constant pursuit of power at the expense of their friendship. Maybe Sasuke makes a decision to leave the village again for more power, and Naruto, tired of his friend's self - destructive ways, snaps and tries to make him see reason.
One interesting scenario could be a fight in an alternate dimension where the rules of chakra are different. This would force both Naruto and Sasuke to adapt new strategies. Another could be a battle where they are forced to team up against a common enemy first before their duel, which would add a complex layer of emotions and dynamics.
One possible interesting scenario could be Naruto using his unique jutsu in Suna. For example, he might use his Shadow Clone Jutsu in a creative way to help with some sort of Suna - related problem, like rescuing people from a sandstorm. Another could be Naruto interacting with Suna characters in a new light, perhaps befriending some of the shinobi there who were previously wary of him.
One interesting scenario could be baby Sasuke and baby Naruto getting into innocent mischief together in the Hidden Leaf Village. Maybe they accidentally let all the chickens loose in the market area while playing a game of chase.
One interesting scenario could be that Naruto and Sasuke discover a new power within themselves during the fight that changes the whole dynamic. Maybe Naruto unlocks a new form of Sage Mode that gives him an edge, and Sasuke responds with a new sharingan evolution.
Well, he might use his reality - controlling power to make himself the most powerful ninja instantly. He could also create a world where ninjutsu has no negative side - effects. For instance, no one would go blind from overusing the Mangekyo Sharingan. Or he could make it so that everyone can understand each other's language without any communication barriers in the ninja world.
One possible scenario could be that they sacrifice themselves to save the village from an ultimate evil. They might combine their powers in a final, desperate move that exhausts them completely, leading to their deaths.
Another scenario could be that they are poisoned by a new, undetectable toxin. As they gradually weaken, they try to find a cure but run out of time. Their deaths would be a great loss, and it could lead to major changes in the political and social structure of the ninja world as everyone copes with their passing.
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.