A third plot could be that Harry is reborn in a time - loop scenario. Every time he dies, he is reborn again at a certain point in his life. He has to figure out how to break this loop while also trying to prevent the tragedies that keep occurring. This could involve a lot of self - discovery and exploring different magical abilities he may not have known he had in his previous lives.
Another plot might involve Harry being reborn into a different family within the wizarding world. This new family could have its own secrets and powers. Harry then has to navigate his new identity while still being aware of Voldemort's impending return. He might have to deal with different loyalties and expectations in this new family dynamic.
One idea could be that Harry is reborn with all his previous memories intact. He uses this knowledge to change the course of events much earlier. For example, he could start befriending Hermione and Ron in a different way, perhaps by being more upfront about his past experiences and the threats they will face.
One idea could be being reborn as Harry's long - lost twin. You could then have a whole new dynamic where you both share the burden of being the Boy Who Lived, but also have your own unique abilities and personalities. Another plot could be being reborn as a Slytherin who tries to change the house's reputation from the inside. You might start off being shunned by the other Gryffindors and friends of Harry, but slowly prove that not all Slytherins are bad.
One interesting plot could be a character reborn with memories of the future. For example, a minor character who remembers Voldemort's rise and fall and tries to change things in a different way. They might try to prevent certain deaths or change the course of the wizarding wars.
One interesting plot idea could be Harry being reborn into the Katekyo Hitman Reborn world with his magical abilities intact. He could use his magic to create unique weapons or defenses, like using a Patronus charm to protect himself from an enemy's attack. Another idea is that he teams up with Tsuna and his friends to take on a new, powerful enemy that threatens both the magical and mafia worlds. Maybe he teaches them some basic magic spells to give them an edge in battles.
One idea could be that Harry Potter is reborn in the Naruto world as an Uzumaki. He could use his magical knowledge in unique ways, like using magic to enhance his chakra control. Maybe he creates new jutsu that combine magic and chakra, such as a spell - enhanced Rasengan.
One idea could be that Harry discovers he has a daughter from a past life or a time - traveling situation. She might inherit some of his magical abilities in unique ways, like being able to communicate with magical creatures on a deeper level. Another could be that she has to face the same kind of challenges Harry did, but in a different era, and she uses her father's legacy as both a source of strength and pressure.
Well, perhaps a cool plot is that as a dragon, Harry discovers ancient dragon magic that has been long forgotten in the wizarding world. He then uses this magic to revive some of the lost magical creatures. Also, his interactions with other magical beings would be different. For example, he might have a unique bond with the centaurs as a dragon.
Well, perhaps in this fanfiction, Harry, now Tsuna, has visions of his past life at Hogwarts during his battles in the KHR world. These visions give him an edge as he can draw on the spells and strategies he used against Voldemort to fight his new enemies. Also, his relationship with Reborn could be really interesting. Reborn might be intrigued by Tsuna's strange bursts of knowledge and skills that seem to come out of nowhere, which are actually remnants of Harry's past magical training.
One idea could be that as a girl, Harry has a different approach to dealing with the challenges at Hogwarts. For example, she might use her charm more subtly to influence others and gain allies. Another could be that her relationships with male characters like Ron and Hermione develop in new and unexpected ways, perhaps with a more sisterly bond with Ron and a different kind of friendship with Hermione.
Perhaps he could use his phoenix form to travel to places that are otherwise inaccessible. He could fly to the Forbidden Forest's most secret corners and discover new magical creatures or ancient magic. Also, his rebirth as a phoenix might give him the power to communicate with other phoenixes, and they could pass on their ancient wisdom to him.
Perhaps in this fanfiction, the reborn Harry as a granddaughter discovers a hidden prophecy related to his former self. This could set him on a journey to either fulfill or prevent it. Also, he could form new friendships that are different from the ones he had in his previous life. Since he's now a granddaughter, the social dynamics might change, and he could use this new identity to his advantage in the magical community.