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.
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.
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.
One popular theme is redemption. Given Obito's past actions, many fanfictions explore his journey towards redemption and how Kakashi plays a role in it. For example, Kakashi might be the one to finally make Obito see the error of his ways.
Most popular ones often focus on their deep emotional bond. Since they have a long history together in the Naruto series, fanfics tend to explore the different phases of their relationship, like their childhood friendship and how it was affected by the events that followed.
They are popular because the relationship between Obito and Kakashi is complex. Their history as friends turned enemies creates a lot of drama. Fans are interested in exploring how Obito's actions impact Kakashi.
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.
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.
Friendship is a key element. Their long - standing bond from their youth is often explored, how it was broken and how it might be repaired. For example, in many fanfics, they recall their days as teammates and the trust they once had.
One great 'kakashi x obito fanfic' is 'The Bond Beyond Time'. It beautifully explores their complex relationship from their early days as teammates to the more tumultuous times. The story delves deep into their emotions and how their bond has endured through all the hardships they faced in the Naruto universe.
There's also 'The Unbreakable Link: Kakashi and Obito'. This one shows their unwavering connection. It has some exciting plot twists that keep you hooked, like how they support each other in difficult situations and how their friendship endures despite all the odds.