Well, Obito could be a key figure in a post - war peace - building process. He might use his influence among the rogue ninja elements (since he was once part of that world) to convince them to come to the negotiating table. His survival could also lead to some interesting relationships. For example, his interactions with Kakashi could be a major part of the story. They have a long and complicated history, and now they could either reconcile or have new conflicts based on Obito's new perspective after the war.
One possibility is that Obito, having survived the war, would be a very conflicted character. He has all this history of pain and destruction, but now he has a second chance. He might team up with Naruto and the others, using his knowledge of the darker side of the ninja world to fight new threats that emerged in the post - war chaos. He could also be on a journey of self - discovery, trying to figure out who he really is outside of being a tool for Madara's plans.
In such a fanfic, perhaps Obito could use his Sharingan powers in new and unexpected ways after the war. He might start to see the world differently and strive to make amends for his past actions. He could use his abilities to help rebuild the villages he once tried to destroy, like Konoha.
Naruto could be one of his allies. Naruto has this knack for seeing the good in people and would probably be willing to give Obito a chance to redeem himself. Also, Sakura, with her skills as a medic - ninja, could be an ally. She might help heal Obito if he was injured during the war and see the potential in him to be a force for good.
Well, in this fanfic, Obito might raise Naruto to be more cynical about the Hidden Leaf Village. Since Obito has his own grudges against the village, he could influence Naruto's perception of it. However, Naruto's own kind heart might still shine through and he could end up trying to change Obito's views while still learning from him. For example, Naruto could use the power and skills he learns from Obito to protect the village in a new way, bridging the gap between Obito's distrust and the village's need for protection.
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.
Another plot twist could be that Obito is secretly training Naruto to fight against an even greater enemy that no one else is aware of yet. This enemy could be an ancient force that is about to awaken, and Obito believes Naruto is the only one who can stop it. So, he's training Naruto in unique and unorthodox ways that seem strange to others at first.
Well, in this kind of fanfiction, Obito might face a lot of challenges in readjusting to the post - war world. Maybe he has to deal with the guilt of his past actions.
In such a fanfiction, Obito might seek redemption. He could use his remaining powers to help rebuild the villages he once damaged. Maybe he would start by teaching the new generation about the true cost of war and how to avoid the same mistakes.
Well, it could be about Kakashi finally finding Obito after a long search. Maybe Obito has changed a great deal, and Kakashi has to come to terms with this new version of his old friend. They might have a battle first due to their different paths, but then they start to talk and remember their past together, like their time as teammates in Team Minato.
The fanfiction could have a plot where Obito's reincarnation is not a normal one. He is reincarnated with a special mission from the afterlife. He has to find a way to bring peace to the shinobi world in a different way than Naruto did. He might have to face new enemies and also deal with the old grudges that still exist among the ninja clans. His reincarnation could also bring about a change in the relationship between the different villages as he tries to use his past experiences to create a more united and peaceful ninja world.
One possible plot could be that Naruto and Obito are forced to merge due to some dark jutsu gone wrong. Their combined form might initially struggle with two different sets of memories and personalities. Naruto's positive and determined nature could start to influence Obito's more cynical side. Eventually, they might use their combined powers to fight a new, powerful enemy that neither could have defeated alone.
One possible plot could be that Obito, having his own complex views on the ninja world, raises Naruto with a different set of values. He might train Naruto in more unorthodox ways, focusing on Naruto's raw power rather than the traditional ninja teachings. Naruto could grow up with a deeper understanding of the Uchiha's pain and Obito's motives, which could lead to a different path in his quest to become Hokage. For example, he might be more willing to question the village's decisions and seek real peace instead of just the village's prosperity.