Well, one possibility is that he joins an organization dedicated to protecting the secrets of ancient ninja arts. He could learn new and powerful techniques that were long forgotten. This would lead to him facing off against enemies who also seek these secrets, and he'd have to use his newfound knowledge and his Uzumaki tenacity to keep the secrets safe.
If he joins an organization, Naruto might become more strategic. Since organizations usually have a set of goals and plans, he'd need to think more about the overall mission rather than just charging in like he used to. His leadership skills could also improve as he might be given tasks to lead a small group within the organization.
Well, he'd probably bring his ninja skills to the table. His ability to use shadow clones could be used for various tasks like surveillance or combat. He might also teach some of the SHIELD agents his chakra control techniques, which could enhance their physical abilities.
In a 'naruto joins obito fanfic', it could start with Naruto being transported to a parallel dimension where Obito has already started his own ninja village. Naruto, seeing the potential in Obito's ideas but also the flaws, decides to join him. He helps Obito to correct his path. For example, Naruto could teach the ninjas in Obito's village about the importance of hope and not giving in to hatred. They could then work together to build a village that is a model for the rest of the ninja world, based on both Obito's and Naruto's ideals.
One possible plot could be that Naruto, disillusioned with the Hidden Leaf Village for some reason, like being wrongly accused or feeling betrayed. He then decides to join the Akatsuki. He might bring in new jutsu and a different way of thinking to the organization. His goal could change from protecting the village to perhaps finding a new way to bring peace in a more radical way.
Well, if Naruto joins Hive in a fanfic, he might bring his ninja skills. He could use his shadow clone jutsu to help with various tasks in the Hive world. Maybe he'd befriend some of the Hive characters and teach them about chakra.
The main antagonist could be Madara. Even though Obito was once following Madara's plan, with Naruto joining Obito, Madara might see this as a threat to his grand scheme. He could try to manipulate events to drive a wedge between Naruto and Obito or directly attack them to stop their new alliance from achieving their goals.
If Naruto joins the Dark Brotherhood in a fanfic, he could bring his unique ninja skills. His shadow clones, for example, could be used for various sneaky missions the Brotherhood undertakes. However, his positive and optimistic nature might be a threat to the Brotherhood's more secretive and often amoral operations. The Brotherhood would either have to adapt to him or try to corrupt his good nature.
Well, the plot could involve Naruto using his ninja skills in the urban environment of L.A. He might use his speed and agility to chase down criminals in ways the regular SWAT team can't. For example, he could run up walls to get a better vantage point during a standoff.
The Akatsuki members themselves would have mixed reactions. Some, like Itachi (if he were still alive in the fanfic), might see Naruto as a potential asset but also a threat to their long - term goals. Kisame might be amused by Naruto's presence and see him as a new source of entertainment. Meanwhile, the Leaf Village elders would be outraged. They would see Naruto as a traitor and start devising plans to either bring him back or eliminate him.