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.
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.
One common theme is redemption. Since they go back in time, both Obito and Kakashi often try to atone for their past mistakes. For example, Obito might try to prevent the events that led him to become evil in the first place.
One great Kakashi x Obito fanfiction is 'The Bonds We Share'. It delves deep into their relationship, exploring how their past experiences shape their interactions in a post - war Konoha. It shows their growth and how they come to understand each other on a deeper level.
One idea could be a story where Female Kakashi and Obito are on a mission together in a mysterious land filled with ancient magic. They have to rely on each other's skills to survive and in the process, they start to see each other in a new light.
There's also 'Time's Redemption'. This fanfiction has a unique take on time travel. Kakashi and Obito are sent back together. They have to work together to change the fate of the Hidden Leaf. The story delves deep into their relationship, exploring how they understand each other better through this time - traveling adventure.
One common theme is redemption. Since they both have a lot of regrets in their original timeline, time travel gives them a chance to fix things, like saving their friends or preventing the destruction of the village.
One idea could be that Kakashi travels back to the moment right before Obito's 'death'. He uses his knowledge of future events to prevent the cave from collapsing on Obito. Then, together they are able to rescue Rin more effectively and change the whole tragic course of events.