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.
Some fanfictions might explore the emotional aspect of their fight. For example, how their past friendship affects the battle. Maybe Kakashi hesitates to strike a fatal blow because of their shared history.
In some fan fictions, there might be a plot where Obito has a change of heart before a major battle with Kakashi. He could start to question his motives and the path he has chosen, leading to a very intense and emotional confrontation with Kakashi that is more about ideology than pure combat.
I'm not sure specifically as I haven't read it. It could be about a variety of things like an adventure, a fantasy world, or a coming - of - age story. Light novels often cover a wide range of genres.
You could also check out Naruto fanfiction groups on social media platforms like Facebook. There are often enthusiasts who share and discuss their favorite fanfictions. Just search for relevant groups, join them, and then look for fanfictions about Kakashi vs Obito.
You could try looking for it in local bookstores that specialize in Japanese or international light novels. They might have it in stock or be able to order it for you.
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.
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.
Often, Obito is attracted to Kushina's strength and kindness. He might try to impress her with his own abilities. Their interactions could involve Obito being a bit clumsy in his attempts at first. Kushina, on the other hand, might find his eagerness endearing and start to open up to him more. They could share stories about their pasts, their dreams, which deepens their bond.