One possible plot twist could be that Sakura discovers a hidden weakness of Madara's during the fight. Maybe it's a chakra point that, when struck, temporarily paralyzes him, giving her an upper hand.
Another plot twist might be that Sakura is actually being influenced by an ancient jutsu without her knowledge. This jutsu makes her fight with a level of ferocity and skill she didn't previously possess, which surprises Madara and changes the course of the battle. For example, the jutsu could be connected to a long - lost clan's power that has now awakened in Sakura. As the fight progresses, she has to figure out how to control this new power while still trying to defeat Madara.
Another plot twist could be that Madara is being controlled by an even greater force when he captures Sakura. And Sakura realizes this and has to find a way to break the control on Madara while also escaping from him. This would completely change the direction of the story and introduce new challenges and opportunities for Sakura to show her strength and intelligence.
Maybe in the fanfiction, Madara has a hidden weakness that only Naruto can sense. For example, Naruto might notice that Madara's control over his Sharingan wavers when he's near a certain type of natural energy. So Naruto uses this to his advantage and lures Madara to that area during the fight.
One possible plot twist could be that the pregnancy is a result of some sort of ancient jutsu gone wrong. Maybe a forbidden technique that was meant to save Madara's life but instead had the side effect of causing Sakura to become pregnant. Another could be that an enemy has somehow manipulated their DNA to create the pregnancy as part of a grand scheme to control the two powerful shinobi.
Perhaps in the fanfiction, Madara kidnaps Sakura because he realizes her potential as a medic - nin. He wants her to heal his old wounds or maybe study her unique healing abilities to find a way to make himself invincible. He could keep her in a hidden lair and force her to perform medical experiments on him.
Well, one possible plot could be that Naruto discovers a new jutsu specifically designed to counter Madara's powerful Sharingan abilities. This jutsu might be related to the Sage of Six Paths' power that he already has. With this new power, Naruto engages in a series of intense battles with Madara, each time getting closer to figuring out Madara's weaknesses.
Perhaps a plot twist could be that Naruto and Madara's mother was from a powerful and secret clan. This clan has a prophecy about two brothers saving or destroying the shinobi world. Naruto and Madara are unaware of this prophecy until later in the story. As they start to discover their true potential together, they realize that they have a choice to make. This could lead to internal struggles within each of them as they decide whether to fulfill the 'saving' part of the prophecy or be swayed by Madara's past desires for power and destruction. It would add a layer of mystery and moral dilemma to the fanfiction.
Well, one possible plot twist could be that Madara's reason for saving Naruto is not entirely selfless. Maybe he has a hidden agenda related to some ancient prophecy in the Naruto universe. He might see Naruto as a key to achieving something greater for himself or his clan.
One possible plot twist could be that Naruto's values are very different from the original. Since he's raised by Female Madara, he might have a more aggressive approach to achieving peace. For example, he could be more willing to use forceful means rather than the diplomatic ways he often tries in the original story.
Well, perhaps in the fanfiction, there's some sort of misunderstanding that leads to the fight. Sakura might think Konan is a threat to her village or friends. Konan, on the other hand, is just defending herself. As the fight progresses, Sakura's physical attacks can't keep up with Konan's paper-based attacks that can transform into various shapes and forms. Eventually, Sakura gets caught in a deadly paper trap and loses her life. It could also be a way to show the harsh reality of the ninja world where even the bravest can fall.
One possible plot could be that they are in a world where enemies have become allies. Madara, with his powerful abilities, and Sakura, with her medical skills and strength, find themselves in a situation where they accidentally get closer and Sakura becomes pregnant. This could lead to a story of them trying to protect their unborn child from various threats in the shinobi world while also dealing with the shock and change in their relationship.