One common theme is the oc trying to fit in. The Akatsuki has its own set of rules and a rather unique group dynamic, so the oc has to adapt. Another theme could be redemption. Maybe the oc has a troubled past and joining the Akatsuki is a way for them to start anew or atone for their sins.
Well, I'm not sure of specific 'oc joins akatsuki fanfiction' off the top of my head. But often in these types of fics, the original character (oc) might have a special power or a unique backstory that makes their entry into the Akatsuki interesting. They could befriend some members while facing challenges from others. It really depends on the creativity of the writer.
One possibility is that Naruto joins Akatsuki to change it from within. He might think he can stop their more evil plans while also learning more about his own powers and the secrets of the ninja world that Akatsuki seems to be involved in.
Well, if Naruto joins Akatsuki in fanfiction, perhaps it's because he's disillusioned with the Hidden Leaf Village for some reason. Maybe he feels betrayed by them. In Akatsuki, he could form unexpected alliances. For example, he might bond with Hidan over their shared brashness in a way, and together they could influence the direction of Akatsuki's actions.
One possible scenario is that Sakura could bring her medical skills to the Akatsuki. She might be able to heal some of the members who are constantly in battle and injured. This could change the group's dynamic as they would no longer have to worry as much about their wounds. Also, her combat skills could be enhanced by learning from the Akatsuki's unique fighting styles.
Maybe Naruto joins the Akatsuki with the intention of spying on them for Konoha. He could pretend to be on their side while secretly sending information back to his village. This would add a lot of tension and secrecy to the story as he has to constantly be careful not to be discovered.
Well, if Naruto joined Akatsuki, he would likely face a huge internal struggle. He has always been against the Akatsuki's actions in the original series. His values of friendship and protecting the village would be put to the test. He might try to change the Akatsuki from within, using his talk - no - jutsu to convince some members to abandon their more evil plans. But he would also be in a difficult position as the Akatsuki is filled with powerful and dangerous individuals.
If Naruto joins the Akatsuki in fanfiction, he could try to change the organization from within. He's a very empathetic person. He might see the pain and reasons that led some of the Akatsuki members to become what they are. For example, he could try to convince Sasuke to leave the Akatsuki if he's there. He could also try to make the Akatsuki less violent and more focused on finding a real solution to the shinobi world's problems.
One possible plot could be that Sakura joins the Akatsuki in an attempt to spy on them for Konoha. She might pretend to be a rogue ninja interested in their goals. However, as she spends time with them, she starts to understand their motives which are not as black - and - white as she initially thought.
Naruto could use his shadow clone jutsu to play pranks. For instance, he could make clones that look like the Akatsuki members themselves and have them do really silly things like dance around in circles or sing out - of - tune. The real Akatsuki members would be really confused at first, thinking one of their comrades has gone crazy.