Well, obviously Naruto's son, Boruto, could be considered as an heir in a sense. He has big shoes to fill and already has his own journey in the Boruto series. Another could be Sasuke's daughter if we were to explore a different line of inheritance. She might inherit some of Sasuke's skills and his brooding nature.
There could also be an entirely new character introduced as the heir. Maybe a distant relative of the Uzumaki clan who has been living in seclusion all this time. This character could bring in new jutsus and a fresh perspective to the Naruto universe. They might have a different upbringing compared to the main characters we know, which could lead to interesting interactions.
Well, one could be a female ninja from the Uchiha clan. She might be strong - willed and have the Sharingan. Another could be a gentle - natured girl from the Hyuga clan, with the Byakugan. And of course, there could be a foreign ninja who has her own unique abilities and catches the heir's eye.
Obviously Naruto would be one of the main characters. There could also be characters from the Harry Potter series such as Harry Potter, Ron Weasley, and Hermione Granger. They might interact with Naruto, helping him understand his new role as the heir of Gryffindor.
It could be a new character introduced specifically for this fanfiction. Maybe a transfer student from a far - off wizarding school with a mysterious Roman heritage.
Perhaps it could be a long - lost relative of Harry Potter himself. Since Harry has so many mysterious aspects to his own story, it wouldn't be too far - fetched for a relative of his to be the heir. Another possibility is a character from one of the minor wizarding families that has been overlooked in the original series but actually has a strong connection to the swords.
It could be a previously unknown character, like a distant relative of one of the main families in the Harry Potter series. Maybe a long - lost cousin of the Weasleys or a descendant of one of the founders of Hogwarts that has been living in hiding.
Naruto himself could be a potential character, perhaps in a mentoring role to the 6th Hokage. Sasuke could also be there, maybe as an ally or a rival in some aspects of the story.
Harry Potter himself could be a potential candidate. Given his unique connection to Voldemort and his own powerful magic, it's not a stretch to imagine him being the heir of some long - forgotten magic. Another could be Hermione. Her intelligence and thirst for knowledge could be signs that she has a deeper connection to a magical heritage. Ron could also be a candidate, as his family has a long history in the wizarding world and there could be some hidden magic in his bloodline.
Tsunade would definitely be one. As the most renowned medical ninja in the village, she could either be Naruto's mentor or a colleague. They could exchange medical knowledge and experiences.
Naruto might interact with Eostia's warriors. They could train together, Naruto showing them his ninja combat skills and them teaching him about Eostia - style combat. There could also be some mysterious characters in Eostia, like an old hermit who has some knowledge about Naruto's sudden appearance in their world and could guide him on his journey in Eostia.
Well, obviously Naruto himself would be the central male character. For the female characters in the harem, Sakura could be one. She might start to see Naruto in a new light when he overcomes his blindness with such tenacity. Hinata could also be part of it. Her shy and loving nature could be a great contrast to Naruto's more outgoing and determined personality in this scenario.