It could be really interesting. Maybe in this fanfic, the future female Deku has unique powers and a different personality from the original Deku. She might be more confident and assertive, using her skills to fight in a new way. The story could involve time travel, where the present - day characters meet her and are shocked by her existence.
One possible plot could be that the future female Deku comes back in time to warn the present - day heroes about a powerful villain that will emerge in the future. So she has to convince them to take action and train harder.
In 'deku meets future deku fanfiction', perhaps the future Deku warns the present one about upcoming threats. He could tell him about villains he'll face in the future and how to defeat them. This would give the present Deku an edge in his battles and also in his growth as a hero.
It could be a story full of sweet domestic moments. Maybe they start their day with a shared breakfast, and Deku leaves for his hero duties while Ochako manages their home. They might have cute arguments over little things like who gets to choose the movie at night.
Perhaps the fanfic would focus on a group of characters who are on a quest to find the most powerful 78b watch in the future. Along the way, they face many challenges and enemies, but the watches they possess have unique abilities that help them. For example, one watch might be able to stop time briefly, while another can heal wounds. They have to figure out how to use these abilities to reach their goal.
One possible plot idea could be that they meet at school for the first time. Maybe Deku is being bullied and Uraraka stands up for him. This would start their friendship early on. They could then discover their shared dreams of becoming heroes together.
Maybe in this fanfiction, Class 1 - A is on a training mission when they accidentally stumble into a time - warp and meet Future Deku. Future Deku could be a super - powerful hero, and he starts to train them in advanced techniques that they haven't learned yet. He might also share some of his future experiences with them, like the battles he has won and the villains he has faced, which would inspire Class 1 - A to strive harder in their hero training.
In this fanfiction scenario, one possibility is that Team Minato would be in awe of Future Kakashi's skills. Kakashi might show them some advanced jutsu that haven't been developed yet in their time. For example, he could display a new form of lightning - style jutsu that is more powerful and precise. This would not only amaze Minato, Obito, and Rin but also inspire them to train harder. They might also be curious about the future of the village from Kakashi's perspective, and he could share some of the challenges and victories that lie ahead.
One possible plot could be that the female Naruto is from an alternate universe. When she meets her male counterpart, they initially have a bit of a culture shock. For example, she might be surprised at how casually he takes some of the village traditions that she holds in high regard. Then they start to learn from each other. She could teach him some of her unique jutsu techniques that are different due to the gender - influenced training in her world, and he could show her new ways of handling the politics within the village. Eventually, they team up to face a common enemy that threatens both of their universes.
Deku could become more cautious. If his future self shows him some mistakes he made in the future, he would be more careful in his actions. For example, he might think twice before making a hasty decision in a battle. Also, he could gain a more mature perspective on life and hero - work, as he gets a glimpse of what lies ahead.
One possible plot could be that Deku has had a really tough day at hero training. He's doubting his abilities and feeling down. Bakugou, who has grown as a person, notices. He might start off a bit rough, like his usual self, saying something like 'Don't be such a crybaby, Deku!'. But then he actually sits down with Deku and shares some of his own insecurities about being a hero. He tells Deku that everyone has bad days and that he's seen Deku's progress and knows he's strong. This comforts Deku and they end up having a more understanding relationship.