One plot idea could be that Dadzawa discovers Izuku has some hidden talents that no one else has noticed. For example, Izuku might be able to sense danger in a unique way. Dadzawa then takes it upon himself to train Izuku privately to hone this skill. Another could be that Izuku gets into some trouble at school, and Dadzawa, as a father - figure, has to step in and help him deal with the consequences while also teaching him a valuable lesson about responsibility. A third idea is that they go on a mission together where Izuku's quick thinking and Dadzawa's experience combine to save the day.
In the 'dadzawa and baby izuku fanfiction', it could also focus on the emotional bond between them. Maybe it shows how Izuku, as a baby, brings out a softer side of Dadzawa. For example, Dadzawa might be more patient and nurturing than he is with others in the story.
Their relationship could develop as Dadzawa starts to see Izuku's determination and begins to trust him more. He might start giving Izuku more challenging tasks which Izuku successfully completes, leading to a deeper bond. For example, if Izuku is given a difficult rescue mission to plan and he does an excellent job, Dadzawa would be proud and their relationship would grow.
A common theme could be growth. As Izuku is a baby, we can expect to see his growth over time, whether it's physical, mental or in terms of his abilities, with Dadzawa playing a role in it.
One idea could be that Izuku is kidnapped by a group who wants to use his knowledge of hero strategies against the heroes. They hold him hostage in an abandoned building. Another could be that a villain with a grudge against All Might kidnaps Izuku as a way to lure All Might into a trap. Maybe a group of anti - quirk fanatics take Izuku because they believe his powerful quirk is a threat to their cause.
One idea could be that Izuku's time quirk allows him to reverse time for a short period during battles. So he can correct his mistakes and outwit his opponents. For example, if he made a wrong move in a fight against a villain, he could reverse a few seconds and choose a better strategy.
A possible plot could be centered around Izuku's struggle to control his Phoenix quirk. Since it's such a powerful and volatile quirk, he often loses control. This causes problems not only for him but also for his friends and the people around him. He then has to seek out an old, reclusive hero who once had a similar quirk to learn how to master it.
Perhaps in the fanfiction, they are in a world where quirks don't exist yet. Baby Izuku and Shigaraki grow up in an orphanage. Izuku is always the one trying to cheer everyone up and bring people together. Shigaraki is more withdrawn but Izuku keeps trying to be his friend. As they grow older, events start to shape them in ways that are different from each other, leading to different paths that are still influenced by their early bond.
Another interesting plot idea is that Izuku's quirk evolution is tied to his emotions. When he experiences strong positive emotions like hope or love, his quirk becomes stronger and evolves in unexpected ways. For instance, it could manifest as a healing ability in addition to his existing powers. This would make his character development more complex as he has to learn to manage his emotions not just for his own well - being but also for the sake of his quirk evolution.
Another plot could involve Izuku being part of a secret society of heroes with vampire quirks. They have their own set of rules and ethics regarding using their powers, and Izuku has to learn to navigate this new world while still aiming to be a regular hero.
A plot could revolve around Izuku feeling a bit down about being quirkless and Tsuyu being there to cheer him up. She takes him to her favorite places in the city, like a small pond where she likes to relax. As they spend time together, they start sharing their dreams and fears. Tsuyu tells Izuku how much she admires his determination without a quirk, and this gives Izuku the confidence boost he needs. Their relationship blossoms from there.