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.
Their relationships would become much stronger. Kakashi would no longer have to bear the guilt of Obito's 'death' and Rin's loss. Obito would be extremely grateful to Kakashi for saving his life and would likely view him as an even greater friend and ally. Rin would also be happy to have both of them by her side, and they could form a very tight - knit team.
One great Rin and Obito fanfiction is 'A Different Path'. It explores an alternate universe where Obito returns to the village earlier. The story delves deep into their relationship, showing how they might have interacted and grown together. The character development is really well - done, and it gives a fresh perspective on their bond.
The sad story of Obito and Rin is a key part of the Naruto narrative. Obito was a young ninja with big dreams and a huge crush on Rin. When Rin was seemingly killed in front of him, it shattered his world. He thought that the ninja world was full of pain and betrayal. This led him to be influenced by Madara. He became one of the main antagonists, all because of his love for Rin and the unbearable pain of losing her. His journey from a hopeful young ninja to a vengeful villain is a tragic consequence of Rin's death.
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.
Obito had a deep love for Rin. He always cared about her and tried to protect her. His love was pure and strong. However, their story was filled with tragedy. Rin's death was a great blow to Obito and changed him in many ways.
A good Rin and Obito fanfiction should have strong characterizations. Since we already know the basic personalities of Rin and Obito from the original story, the fanfiction should build on that and show new aspects of their characters. For example, how Obito might have changed if Rin had survived.
Kakashi is known for his laid - back yet highly skilled nature. His influence on Naruto could be in terms of teaching him to be more strategic in battles. Rin, being kind - hearted and having a strong sense of care, would give Naruto the emotional support he lacks. So Naruto might become more balanced in his approach to life and ninja - hood.
Another common theme is the exploration of their past relationship. Fanfics often go back to their childhood days and show how their feelings for each other started. This gives readers a deeper understanding of why they are so important to each other.
One common theme could be unrequited love. Given the complex relationship between Obito and Rin in the original Naruto story, fanfics might explore the idea of one of them having feelings that the other doesn't initially recognize. Another theme could be redemption. Obito has a rather dark past in the series, and fanfics might show how his relationship with Rin could be part of his journey towards redemption.