Besides Obito, Sasuke could be a main character in this fanfiction. Sasuke, with his own journey of redemption and his understanding of power and the ninja world, could have an interesting dynamic with the reincarnated Obito. Also, Sakura might play a role. She could be the one who tries to heal the reincarnated Obito, both physically if he is injured during his new adventures and emotionally from the traumas of his past life.
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.
Minato might also be a prominent character. As their teacher, he can influence the way Obito and Kakashi interact. In some fan fictions, he could be the one to help them resolve their differences or provide some crucial information about their past that changes their current situation.
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.
There could also be interactions with the new generation of ninjas. They might view Obito as a sort of legend or a cautionary tale. Their fresh perspectives could either inspire Obito to change further or make him feel even more out of place in this new post - war ninja world.
One possible fanfiction could be about Naruto and Obito teaming up to face a new, powerful enemy. They could combine their unique skills, like Naruto's Rasengan and Obito's Kamui. Their relationship could start off rocky due to their past differences but gradually turn into a strong bond as they fight side by side.
Well, it could be about Sakura somehow being related to Obito in a reincarnation context. Maybe it involves Sakura having memories or powers that are linked to Obito from a past life. It might explore how this new connection changes their relationship in the Naruto universe, like if Sakura starts to understand Obito's past actions better or if she gains new abilities because of this reincarnation bond.
In a Naruto - Dragon Ball Z crossover, Goku could be a great character to cross with Obito. Goku's pure - hearted nature and his super - strong combat abilities would contrast and interact interestingly with Obito's more complex and often - conflicted character.
Superman could be paired with Obito in a crossover. Superman's pure - heartedness and incredible powers could influence Obito. They could work together to protect a city under threat. Obito might be in awe of Superman's abilities at first but then find ways to contribute with his ninja techniques.
In this kind of fanfiction, Naruto might first try to understand Obito's motives. He could see the pain and loneliness that drove Obito to his dark path. Maybe Naruto would try to convince Obito to give up his evil plans and return to the side of good. They could form an unlikely alliance against a common enemy, like Madara or Kaguya. Naruto's positive attitude and Obito's powerful abilities would make a very interesting combination.
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.