One plot twist could be that they find out a traitor in Suna who is secretly working for an enemy of both Konoha and Suna. This would put them in a difficult situation as they have to figure out who to trust.
A possible plot twist is that there is a long - lost prophecy in Suna that involves Naruto and Sasuke. This prophecy could be something that the current leaders of Suna are trying to keep hidden. When Naruto and Sasuke start to uncover it, they are met with resistance from some and help from others. This would add a whole new layer of mystery and adventure to their trip to Suna.
Perhaps they arrive in Suna only to discover that the mission they were sent on was based on false information. And then they are framed for something they didn't do. They have to clear their names while also dealing with the real threat that is lurking in Suna. This would test their friendship and their ninja skills.
One possible plot twist could be that Naruto has a secret family connection to Suna. Maybe his mother was from Suna and was sent to Konoha on a mission and ended up staying. This would change the whole dynamic of his relationships and how he is perceived in both villages.
A simple plot could be that they are invited to join as a sign of a new era of cooperation. Naruto and Sasuke accept and immediately start to work on improving relations. They hold joint training sessions for the ninjas of both villages, which helps in building trust and camaraderie.
Another plot twist could be that an enemy uses their relationship against them. The enemy could spread rumors or false information to create chaos and turn the ninja world against them. Naruto and Sasuke would then have to fight not only to protect their relationship but also to clear their names and prove that their love doesn't mean harm to the ninja world.
One possible plot twist could be that Naruto, upon getting Sasuke's Rinnegan, starts to see visions of the past and future of the Uchiha clan. This new power might make him question his own beliefs and the relationship between the Senju and Uchiha. He could see the events that led to Sasuke's decision to give him the Rinnegan and struggle with the responsibility that comes with this powerful dojutsu.
Maybe Naruto leaves to Suna because he has some personal issues in Konoha. He could be seeking a fresh start in Suna. There, he might meet new friends and foes alike. He could get involved in Suna's internal politics or power struggles while trying to prove himself as a valuable ally.
Well, in a 'naruto lives in suna' fanfiction, perhaps Naruto is exiled from Konoha for some reason. He then finds a new home in Suna. He starts training with the Sand ninjas and discovers new aspects of his chakra control. He also gets involved in the internal politics of Suna, trying to bring peace between different factions within the village.
Well, one possible plot could be that Naruto, for some reason, is found in Suna and taken in by a family there. Maybe he's lost during a mission near Suna. He then has to adapt to the Suna culture which is different from Konoha's. He might learn new jutsus specific to Suna and form new friendships with Suna shinobi.
One possibility could be that Naruto goes to Suna to help them with a new threat. Maybe there's a powerful enemy that only Naruto's skills, like his Rasengan and shadow clone jutsu, can deal with. He then starts training some of the Suna ninjas in new techniques, leading to stronger bonds between Konoha and Suna.
Well, in the fanfiction, a likely plot development is that Naruto's newfound power, perhaps a unique form of Rasengan, is crucial in the fight against Itachi. Sasuke, on the other hand, is initially blinded by revenge but Naruto helps him see that there's more to Itachi's actions. This could lead to a situation where they don't actually kill Itachi but rather free him from whatever binds him to his 'evil' deeds. The fanfic might then explore how they deal with the consequences of not following through with the kill.
One possible plot twist could be that Sasuke has been under a genjutsu that makes him target Sakura, and Naruto has to break the genjutsu first to truly save her. Maybe the one who cast the genjutsu is a new, powerful enemy who wants to disrupt the bond between Team 7. Naruto, with his strong will and newfound powers, manages to find the source of the genjutsu and free Sasuke from its control, thus saving Sakura from harm.