Fanfiction is a realm of limitless creativity. The concept of Pein as Sakura's father in fanfiction might seem strange at first, especially considering their different roles and storylines in the original Naruto series. But that's the beauty of fanfiction. Writers can break the boundaries of the original story. They can create backstories and relationships that were never imagined in the official plot. It could be a way to explore how Sakura's character might have developed differently if she had such an unexpected family connection. Maybe it would change her goals, her relationships with other characters like Naruto and Sasuke, and her overall place in the Naruto universe. It's all about the author's imagination and what they want to explore within the framework of the Naruto world, even if it's far from the original concept.
Well, in fanfiction, the idea of Pein being Sakura's father could be a really interesting concept. Maybe the author wanted to create a new dynamic between two characters from different story arcs in Naruto. But it's important to remember that it's not part of the official story. It could add a whole new layer of drama and character development in the fan - created world of the story.