Often, Sakura becomes strong through intense training. She might train under a powerful master or by herself, pushing her limits. For example, she could be practicing her chakra control day and night to be able to use stronger jutsus.
I'm not sure if there is such a specific fanfiction. Fanfiction can cover a wide range of themes and interpretations, but a 'perverted' aspect might not be in line with the general positive and creative nature of most fan works. It's possible that there could be some out - there that distort the characters in this way, but it's not a common or recommended type.
One great fanfiction could be 'Sasuke's Homecoming'. In it, Sasuke returns and Sakura has become a very strong medic - ninja. She is able to hold her own in battles and also helps Sasuke deal with his inner demons. Their relationship also develops in a very interesting way as they both grow stronger together.
Well, in such a fanfiction, Sakura's strength would be a central focus. She could be shown training hard and achieving new levels of power, perhaps even surpassing some of her peers. As for Sasuke, his brooding and complex personality would add depth to the story. There might be scenes where Sakura tries to understand Sasuke better or where Sasuke starts to see Sakura in a new light. And of course, the fanfiction might also include other characters from the Naruto series interacting with them, like Naruto being a mediator or a rival in some aspects of their relationship.
In this kind of fanfiction, Sasuke could die from a sneak attack. He might be so focused on his main target during the Wave mission that he doesn't notice another hidden threat. And this hidden enemy could strike him when he least expects it, leading to his death. For example, an assassin could be hired to specifically target Sasuke and use some sort of poison or a deadly jutsu that he can't defend against in time.
Sasuke would probably be very guarded at first. He's not used to dealing with something so innocent and vulnerable. He might be suspicious of the baby's presence and think it's some sort of trap.
One common theme is power dynamics. Since Naruto is strong, it often explores how that strength interacts with a female Sasuke who also has her own power. For example, they might train together and Naruto helps Fem Sasuke reach new levels of power.
Sasuke would be furious. He's always been protective of Naruto in his own way. He would immediately start looking for her, using all his skills and resources. He might even go on a rampage if he thought Naruto was in serious danger.
On the other hand, Sasuke could be very stoic about it on the surface but internally be in turmoil. He might start to analyze his own actions and whether he had missed any signs from Sakura. He could also be the type to immediately start thinking of ways to win Sakura back if he realizes he can't stand the thought of her with someone else.
In the 'naruto is protected by sasuke fanfiction', Sasuke's protection of Naruto could be multi - faceted. Sasuke, being a powerful ninja, would first of all use his physical strength and speed to block attacks aimed at Naruto. Emotionally, his bond with Naruto would make him extremely vigilant. He might sense Naruto's distress from afar and rush to his aid. In terms of strategy, Sasuke would likely plan their movements carefully when they are in dangerous situations, ensuring Naruto is always in a relatively safe position. His ability to quickly analyze a battle situation and react accordingly would be crucial in protecting Naruto.