One possibility could be that Harry, with his knowledge of magic and experience in fighting dark forces, takes Tsuna under his wing in the magical world. He could teach Tsuna about different spells and how to handle magical creatures, which would be a new and exciting experience for Tsuna who is used to his own world in 'Katekyo Hitman Reborn!'.
In a 'Harry Potter raises Tsuna' fanfiction, it could start with Harry accidentally stumbling upon Tsuna in a magical cross - over event. Harry, seeing Tsuna's potential, decides to raise him as his own. He would expose Tsuna to the wizarding culture, like the Quidditch matches. Tsuna, on the other hand, could bring some of his street - smart skills from his own world. Harry would have to deal with Tsuna's unique personality and help him fit into the magical society while also protecting him from any threats that might come their way.
The plot could involve a prophecy that ties Tsuna and Harry together. Harry, being the hero he is, feels responsible for Tsuna. He adopts Tsuna and brings him to live in the wizarding world. Tsuna is amazed by all the magical things around him, from the moving portraits to the flying broomsticks. Harry teaches Tsuna about the dark forces in his world and how to fight them. Tsuna, with his own tenacity, starts to train hard. Along the way, they make new friends together and face many challenges that test their bond and their magical abilities.
Well, perhaps the plot could involve Harry having to fend for himself from a very young age in the wizarding world. He might have to figure out magic on his own, without much guidance from adults. Maybe he starts exploring the secrets of Hogwarts by himself earlier than in the original story, leading to all sorts of unexpected adventures.
Well, in this fanfiction, Kakashi might introduce Harry to the concept of chakra. Since Harry has magic, Kakashi could find a way to combine the two powers. Maybe Harry would learn to use chakra to enhance his spell - casting speed or accuracy. And Kakashi would also help Harry deal with his emotional traumas, like the death of his parents, in a more ninja - like, stoic way.
Well, in this fanfiction, Deadpool might raise Harry Potter in a world where the two universes collide. Deadpool could introduce Harry to the concept of fourth - wall breaking, which would be really strange for Harry. He could also take Harry on adventures that involve both the wizarding world and Deadpool's own crazy world filled with mercenaries and mutants, leading to some really unique and comical situations.
Maybe Harry starts raising chickens because he wants to have a normal, non - magical hobby. He finds some regular Muggle - like chickens in a nearby village. As he raises them, he realizes that they have an uncanny ability to sense dark magic. So, they become like an early warning system for any approaching danger at Hogwarts. This could lead to all sorts of adventures where Harry has to protect his chickens from dark wizards who want to use their power for evil.
In such a fanfiction, Harry might raise Naruto in a way that combines the values of both the wizarding world and the ninja world. He could introduce Naruto to the concept of different magical creatures, which Naruto could then try to incorporate into his ninja training. Maybe Naruto would learn how to communicate with magical animals like Hedwig, and use that knowledge to better understand the summons in his own world. Also, Harry could help Naruto with his studies, which would be a huge change for Naruto who wasn't that good at traditional schoolwork at first. This would not only make Naruto more well - rounded but also give him an edge in the ninja world with his new - found knowledge.
Hermione would be really interesting. She could help Tsuna with his studies, whether it's about the magical lore of the Harry Potter world or just general knowledge. She might be a bit strict with Tsuna at first, but as time goes on, they could become good friends. Another interesting character would be Dumbledore. He could offer his wisdom and guidance to Harry in raising Tsuna, and might also see some special qualities in Tsuna that could be important for the future of the wizarding world.
In such a fanfiction, perhaps Harry Potter feels a sense of duty to raise Delphini despite her being Voldemort's daughter. He might see her as a chance to break the cycle of dark magic. He could raise her with the values of love and friendship, trying to turn her into a force for good in the wizarding world.
Well, it could start with Harry finding an injured dragon. Out of compassion, he decides to take care of it. He might use his magic skills and knowledge from Hogwarts to nurse it back to health. As the dragon grows, he has to find ways to keep it under control. He could face problems like the dragon's growing appetite and its natural instinct to be wild. Maybe he even has to enlist the help of his friends, like Ron and Hermione, to keep his dragon - raising a secret from the school authorities.
The fanfic could start with Harry accidentally stumbling upon a chimera egg. He takes it upon himself to hatch and raise the chimera. He might face many challenges, like when the chimera starts to grow and becomes difficult to control. He could seek help from Hagrid, who has experience with magical creatures. Together, they could train the chimera. And as the chimera grows, it could become a powerful ally for Harry in his fight against Voldemort. It might even have some special powers that can help in battles, like breathing fire to fend off Death Eaters.