A new character could be introduced as the antagonist. Maybe someone who has also time - traveled and has their own agenda for the past. This character could be trying to preserve the original timeline for some reason, or they could be trying to create an even worse future. They would oppose Obito and Kakashi at every turn, creating a lot of conflict and drama in the fanfiction.
One common theme is redemption. Given Obito's past actions, many fanfics explore his journey towards redemption in the context of his relationship with Kakashi. Another theme is friendship turned into something deeper, as they have a long - standing connection that can be developed in various romantic or deeply emotional ways.
In an 'Obito kills Kakashi' fanfiction, it could start with a long - standing grudge. Maybe Obito discovers some new information that he believes Kakashi has been hiding from him all these years. This enrages him so much that he decides to take revenge and kills Kakashi in a fit of rage during a battle.
You can try fanfiction websites like Archive of Our Own (AO3). It has a vast collection of fan - created works, and there's a good chance you'll find 'kakashi kisses obito fanfiction' there. Just use the search function and type in the relevant keywords.
There could be a 'kakashi kisses obito fanfiction' that focuses on a time - travel plot. Obito travels back in time and gets to know Kakashi in a different way. As they train together and face challenges side by side, their bond strengthens and leads to a romantic moment with a kiss. It's a really interesting take on their relationship as it plays with the concept of changing their fated paths.
Some fans would be really shocked and sad. Kakashi is a very popular character, and his death at the hands of Obito would be a huge blow to many. They might feel angry towards the author for creating such a tragic scenario.
In this alternate storyline, it could lead to major changes in their relationship and the overall plot. Maybe Obito's feelings would prevent him from going down the dark path he did originally.
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.
A lot of fanfictions explore their relationship from a more emotional and psychological perspective. These stories might delve into how Obito's fall affected Kakashi and how Kakashi coped with the guilt. They could also show Obito's journey of redemption from Kakashi's point of view. These types of fanfictions are often deep and meaningful, without any inappropriate content.
One great 'Obito x Kakashi fanfic' is 'The Bonds Beyond Time'. It delves deep into their complex relationship, exploring how their past experiences shape their interactions in a very emotional way. The author does an excellent job of showing the growth of their relationship from their days as comrades to something more profound.