A fanfic could show Sakura sacrificing herself to save Sasuke. This would be a very emotional and heroic end for her. Sasuke would then have to live with the guilt and the memory of her selfless act.
One idea for a fanfic is that Sakura dies due to a disease that she couldn't cure herself. This would show her vulnerability despite being a strong medical ninja. Sasuke would be devastated and might turn away from the world for a while, until he realizes that he should honor her memory by protecting others.
If Sakura dies in a fanfic, it could have a huge impact on the whole Naruto -verse within that story. Her friends like Naruto would be deeply affected. Naruto might feel like he failed to protect her, just as he felt about other losses in his life. And for the medical ninja community in the fanfic, her death could be a big blow as she was a talented medic.
It might explore different aspects of Sasuke and Sakura's characters within the context of a fanfic. For example, it could show Sakura with different abilities or Sasuke having a different attitude towards her. Since it's a fanfic, the author has the freedom to deviate from the original storyline and create something new. It could also be about their relationship in a different time period or setting, like in a modern - day AU (alternate universe) or in a completely fictional world.
Sakura's injury can strengthen the SasuSaku relationship. It can make Sasuke realize how much he values her, and he may start to show more affection. For instance, he might give her a gentle touch or a worried look, which is different from his usual cold demeanor.
Well, in such a fanfic, perhaps Sakura could gain new powers. With the seal breaking, she might be able to access a hidden reservoir of chakra. This could lead to her being more formidable in battle and changing the power dynamics within the Sasusaku relationship.
It could be Orochimaru. He's always been interested in Sasuke and might see kidnapping Sakura as a way to manipulate Sasuke. He could use Sakura as a guinea pig for his experiments or as a bargaining chip to get Sasuke to come to him.
Well, one possibility could be that it's a dark fanfic where an enemy of Sakura kidnaps her to get to Sasuke. Maybe they want to use her as bait to lure Sasuke into a trap. Since Sasusaku is a popular pairing, the kidnapper might think that Sasuke would do anything to save Sakura.
Obviously, Sasuke would be affected. Since it's a Sasusaku - related fanfic, any change in Sakura would impact their relationship. He might have to adjust to a more powerful Sakura, or he could be worried about the consequences of the seal breaking.
One possible fanfic could be that Sakura's parents die in a tragic accident. Maybe a natural disaster like an earthquake hits their village and they sacrifice themselves to save Sakura. This would be a very emotional and character - building event for Sakura, leading her to become stronger and more independent in the story.
The fanfic can use the reactions of other characters. If Sasuke starts to notice Sakura's strange behavior when certain topics are brought up, like her flinching when someone mentions a particular mission. His curiosity can then lead to the discovery of her dark past. Also, the use of her internal monologue can be very effective. She can constantly be thinking about her past mistakes or traumas, like how she might have let someone down during a critical moment in her past.
Based on the title, the main characters are likely to be Sasuke and Sakura. Since it's a SasuSaku fanfic, they are usually the central focus.