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.
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.
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.
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.
In this fanfiction concept, it might be interesting if Harry, as a Targaryen, is born with the ability to communicate with dragons in a more profound way than the typical Targaryen. This could be because of his past life experiences with magical creatures. He could use this connection to his advantage, uniting the different factions in Westeros. Also, his memories of the Sorting Hat might influence how he views the different houses or families in Westeros, and he could strive to create a more inclusive society.
One idea could be that Harry is reborn into the world of 'Reborn' with his magical abilities intact. He could use magic to solve the mysteries and challenges in the 'Reborn' world, like helping Tsuna in a unique way. Another plot could involve the magic of the 'Harry Potter' universe somehow getting intertwined with the flames in 'Reborn'.
One idea could be being reborn as a muggle - born wizard who has a unique ability to communicate with magical creatures in ways others can't. This could lead to all sorts of adventures in the Forbidden Forest and uncovering secrets about the creatures that help in the fight against Voldemort.
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.