In this fanfiction, Obito's development can be quite interesting. He may begin with his own motives that are not entirely pure. However, as he spends more time with Naruto, he starts to see the world through Naruto's eyes. This could lead to him becoming more empathetic towards others in the ninja world. For example, he might start to understand the importance of protecting the village and its people, just like Naruto does.
One possible reason could be that Obito sees Naruto as a means to fulfill his own twisted ideals. Maybe he wants to shape Naruto into a weapon against the Hidden Leaf. Another reason might be that he feels some sort of connection to Naruto because of their shared experiences of being alone and ostracized in the past. He could also think that by taking Naruto as a baby, he can prevent Naruto from becoming the hero the village wants him to be, thus disrupting the balance in the ninja world.
One unique plot point could be Obito teaching Naruto some of his own special jutsu that he developed during his time as a rogue ninja. Another might be Obito using his knowledge of the darker side of the ninja world to protect Naruto from certain threats that the normal Konoha ninja might not be aware of.
The story could develop with Obito training Naruto in his own way, away from the values of the Hidden Leaf. Naruto might grow up with a different set of skills and a different view of the ninja world. There could be a lot of internal conflict in Naruto as he discovers the truth about his origins and the fact that he was taken from his village. This could lead to a showdown between Naruto and the Hidden Leaf at some point, or Naruto might try to find a middle ground between Obito's teachings and his own sense of right and wrong.
One possible motive could be to gain control over Naruto's power. Since Naruto has the Nine - Tails within him, Danzo might want to use that power for his own political or military gains. He's always been power - hungry and sees Naruto as a tool to achieve his goals of making Konoha stronger in his own way, which might involve more underhanded and controlling methods.
It could also be a completely new character introduced into the fanfiction. A foreign ninja who was inspired by some of Danzo's ideas (not the bad ones) and comes to Konoha to take on the role of successor, bringing in new perspectives and ways of doing things.
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.
It could also be due to Naruto's outcast status in the village initially. Danzo might think that banishing Naruto would be an easy decision as Naruto doesn't have many supporters at first. He might believe that by getting rid of Naruto, he can maintain the status quo in the village and prevent any disruptions that Naruto's presence might cause in the future.
Well, in some versions, Naruto might use his influence among the villagers. After Pain's attack, the village is in a state of rebuilding and re - evaluating. Naruto, being a hero, has the ears of the people. He could start by presenting evidence of Danzo's underhanded deals, like his connection to Orochimaru perhaps. Maybe he found some secret documents during the chaos that Pain caused, which link Danzo to unethical experiments or power - grabbing within the village.
Well, the reborn character could explore Obito's Sharingan powers in new ways. Instead of using them mainly for combat like Obito did in the original story, they could focus on using the Sharingan to understand the emotions of others. For example, they could use it to detect lies and hidden motives, which would be a unique twist on the power.