Maybe the horns are a result of some ancient magic that was cast on his family long ago. Harry would then have to go on a journey to discover the origin of this magic and how to control or get rid of the horns. Along the way, he might face discrimination from some wizards who are afraid of the unknown.
One possible plotline could be that Harry's horns are seen as a sign of great power in the wizarding world. Some might see him as a prophesied savior in a different way than in the original story. The Dark forces may either try to use him or destroy him because of this unique feature.
It could be that the horns give Harry some special abilities, like enhanced magic sensing or the ability to communicate with certain magical creatures that are only attracted to those with such physical features. His friends at Hogwarts would have mixed reactions at first, but gradually accept him and help him explore the potential of his horns.
One possible plotline could be that Naruto's wings make him an outcast in the village at first. People are scared or jealous of his unique feature. But as he grows, he learns to use his wings in combat, perhaps in a new style of ninja fighting that combines aerial maneuvers. He could also use his wings to reach places quickly during missions, giving him an edge.
One possible plotline could be that Harry discovers his celestial nature and has to learn to control his newfound powers. He might face challenges from both the wizarding world, who are suspicious of his new abilities, and the celestial realm, where there could be those who oppose his presence.
One possible plotline could be that Krum, being a well - known Quidditch star, trains Harry in Quidditch from a very young age. Harry might grow up with a different set of skills and a more international perspective on magic due to Krum's Bulgarian background. He could also be introduced to different magical cultures earlier.
One possible plotline could be that Harry is so focused on his fight against Voldemort that he doesn't have the emotional space to develop feelings for Ginny. He might see her as just a friend or even as a younger sister figure. For example, he could be constantly training, researching dark magic defenses, and leading the Dumbledore's Army, leaving no room for romantic thoughts about Ginny. Another aspect could be that Harry has unresolved trauma from his past, like the death of his parents, which makes him hesitant to get involved in a romantic relationship with Ginny.
If Harry was raised in Japan, he could grow up in a world where magic is intertwined with Japanese mythology and culture. He might study at a Japanese wizarding school. His upbringing would expose him to things like Japanese magical creatures, which could be different from those in the UK. He could also have a different set of values instilled in him due to the Japanese cultural influence.
Maybe the horns are a sign of a new power awakening within Naruto. He could initially be afraid of them and hide them, but as he discovers their potential, he learns to embrace this new aspect of himself and use it to protect the village in ways he couldn't before.
One possible plotline could be that Harry discovers Snape's true motives much earlier. Maybe he stumbles upon Snape's memories that show his complex relationship with Harry's mother. This new understanding makes Harry see Snape in a different light. They start to have secret meetings where Snape teaches Harry advanced magic, away from the prying eyes of others at Hogwarts. Their relationship gradually evolves from one of enmity to an unspoken bond.
One possible plotline could be that Harry grows up with a very different set of values. Since Lucifer is often associated with rebellion and a certain kind of dark knowledge, Harry might be taught to question authority in a more extreme way than in the original series. He could also have some very unique magical abilities that are influenced by Lucifer's nature, perhaps abilities related to darker forms of magic.
Another plot could involve a sort of magical exchange. Orochimaru, being a master of some dark and strange jutsu in his own world, might offer to teach some of his knowledge to certain dark wizards in the Harry Potter world in exchange for something valuable. Harry Potter and his friends would have to prevent this knowledge transfer as it could tip the balance of power towards the dark side in their world. They might need to seek help from some of the more powerful and wise wizards like Dumbledore to outwit Orochimaru.
Another plot could involve Medusa being a part of a long - forgotten magical mystery that is somehow related to Harry's destiny. Harry, with his inquisitive nature, starts to research about her. As he gets closer to the truth, he has to face the danger of being turned to stone. But through his courage and the help of his friends, he manages to break the curse on Medusa, and in return, she helps him in his fight against Voldemort.