In some fanfictions, Sasuke and Sakura's relationship is often portrayed as a more developed romantic one. Sakura is usually shown as being deeply in love with Sasuke still, while Sasuke may be slowly coming to terms with his feelings for her. Karin's relationship with Sasuke is more complex. She has an unrequited love for him, which can create some tension. Karin and Sakura's relationship can range from being rivals to begrudging allies depending on the story.
The relationships are portrayed in diverse ways. There are fanfictions where Sasuke is still somewhat distant from both Sakura and Karin. He is focused on his own goals and they are trying to break through his shell. Sakura's relationship with Karin can be really interesting. They might start off as not getting along because of their feelings for Sasuke, but as the story progresses, they find common ground. Maybe they both realize that Sasuke has his own path and they should focus on their own growth. So they become friends and support each other in their ninja careers, while Sasuke is left to figure out his place in their new dynamic.
In some fanfictions, Sasuke's relationship with Sarada is full of misunderstandings. Sarada may feel that her father doesn't care about her. Sakura then acts as a mediator between them. Their relationship is also depicted as a strong family unit where they support each other in times of danger. For example, when Sarada is in trouble, Sasuke and Sakura will put aside their differences and come to her rescue.
Often, in such fanfictions, the relationships can be really out of character. Naruto might be made overly possessive of Sasuke, and Sakura might be pushed to the side as an unwanted third party. But it's important to note that these are just fan - created ideas and not in line with the official Naruto storyline. The lemon aspect usually adds a lot of adult - like romantic and physical elements that are not suitable for all audiences.
The relationships can be developed by putting them in difficult situations together. For example, if they are trapped in a dangerous place like a maze - like dungeon. They have to rely on each other's skills. Sasuke's combat abilities, Sakura's medical knowledge and Karin's sensory skills. As they work together to escape, they start to understand each other better. Karin might see that Sakura is not just a rival for Sasuke's affections but a strong and capable ninja. And Sakura might realize that Karin has her own insecurities and strengths.
Karin could be heartbroken. She might initially be angry and feel betrayed, lashing out at Sasuke for choosing Sakura over her.
In the realm of fanfiction, almost any scenario is possible. Regarding Sasuke divorcing Sakura for Karin, it may exist. Fanfiction authors draw inspiration from the source material and then take it in new directions. The idea might stem from Karin's past feelings for Sasuke and some fans' desire to see how such a relationship shift would impact the characters. It could also be a way to explore the characters' personalities more deeply, for example, how Sakura would cope with such a betrayal and how Karin would handle being with Sasuke in that context.
There probably is. Fanfiction writers like to take existing characters and create different storylines. But it's important to note that this isn't part of the official Naruto story. In the original, Sasuke and Sakura are a couple, and Karin has her own relationship with Sasuke which is more of comradeship in the official plot. Fanfiction just gives people the freedom to deviate from the original.
Sakura might be heartbroken. She's been in love with Sasuke for so long. She could initially go into denial, thinking it's just a temporary thing. Then she might get angry and vow to prove herself to Sasuke, perhaps by becoming an even stronger ninja.
There could be. Fanfiction writers sometimes come up with very creative and sometimes controversial ideas. However, this particular plot would be quite a deviation from the original story's themes of loyalty and friendship. In the original, Sasuke has his own complex relationships that don't involve such unfaithful behavior in this way.
Another way could be through his influence. Sasuke has a certain presence and leadership quality. He might make it clear to Karin that any harm to Sakura would not be tolerated. This could be through direct communication or by making it known in their group or among their peers that Sakura is under his protection.
In many fanfictions, Sasuke and Sakura's arguments are shown as a key part of their relationship growth. They might argue about Sasuke's missions and the danger he puts himself in. Sakura, being worried, confronts him. These arguments can be filled with unspoken emotions and desires, and through them, the authors can dig deeper into their characters' minds and how they truly feel about each other.