Perhaps Rose is a mysterious child with a prophecy attached to her. The wizarding world is on edge about her existence, but Harry, believing in the good in people, adopts her to protect her from those who would use the prophecy for their own evil ends. He becomes her protector and mentor, guiding her through a world full of secrets and danger.
In a 'harry adopts rose fanfiction', perhaps Rose has some special power or connection that draws Harry to her. Harry might adopt her to keep her safe from those who would misuse her power. He then has to navigate the challenges of being a single parent in the wizarding world, like getting her enrolled in Hogwarts, dealing with other parents who might be suspicious of his motives, and helping Rose control her magic as she grows up.
Maybe some of Draco's old Slytherin friends or acquaintances make an appearance. They could either support or oppose Draco's decision to adopt Rose, depending on their own views and how they've changed since their school days.
Another interesting plot could be Rose's discovery of Draco's past and how she helps him come to terms with it. She might find out about his family's dark history during the wizarding wars and be a source of light and forgiveness for him.
Yes, there are some fanfictions with this concept. It's an interesting take on the Harry Potter universe as it flips the typical relationship between Harry and Voldemort. In these fanfictions, the story often explores how Voldemort's actions change when he takes on the role of an adoptive figure to Harry, who has been abused. It can lead to some really unique character developments and plot twists.
One great fanfiction in this genre is 'A New Beginning' where McGonagall steps in to rescue Harry from his abusive relatives. It beautifully shows how she nurtures him and helps him grow in confidence.
Another theme is self - discovery for Harry. With the influence of the MC, Harry gets to explore different aspects of himself. For example, he might discover new magical abilities or gain more confidence in his identity as a wizard. In some fanfictions, the MC helps Harry to look beyond what he thought was possible for himself.
Perhaps Bruce Banner adopts Harry Potter after the events at Hogwarts. He takes Harry to the world of science, showing him things like advanced laboratories and scientific research. Harry, in turn, shows Bruce the wonders of magic. Their bond grows as they learn from each other, and together they face new threats that combine elements of both the magical and scientific worlds.
Well, perhaps Harry discovers an orphaned baby in a dangerous situation. He decides to take the baby in out of the kindness of his heart. He then has to learn how to take care of a baby while also dealing with his own wizarding world responsibilities. Maybe he asks his friends like Hermione for advice on baby - care.
In this fanfiction, perhaps Harry adopts Tsuna because he senses a great power within Tsuna that needs to be guided. Harry could use his experience with the Dursleys and Hogwarts to give Tsuna a stable and loving home. He might train Tsuna in both magic and combat, and together they could face new threats that are a combination of the threats from Tsuna's world and the wizarding world, like dark wizards teaming up with Tsuna's enemies.