Another common character could be Hagrid. He was such an important part of Harry's life at Hogwarts and might continue to be in the fanfiction, perhaps coming over to the Potter family's house to show the kids some new magical creatures or give them some advice on their magical studies. There could also be characters from the Ministry of Magic, like some new Aurors who interact with the Potter family in different ways, either as friends or as those who are a bit suspicious of their activities.
Obviously, Harry Potter himself is a central character. His sister would be the new addition. Hermione and Ron are likely to be there as well. They are Harry's best friends in the original series and would probably play important roles in the fanfiction too. Dumbledore might also appear, as he is a very important figure in the wizarding world and could guide the sister in her magical journey.
Ron could also be there. He might be initially scared of the dragon but then grows to like it. His loyalty to Harry would make him support Harry's decisions regarding the dragon, even if they seem risky. For example, when they need to hide the dragon from the Ministry of Magic, Ron would be right there with Harry, coming up with crazy but effective plans.
Dobby is often a common character in such fanfictions. Since he was a well - known house - elf who managed to break free from his binds, he can be a source of inspiration or a mentor figure for other bound family elves in the stories.
Obviously, Harry Potter himself is the central character. Hermione and Ron are also likely to be important characters as they are Harry's closest friends and often accompany him in his adventures.
Hermione is often in these fanfictions. She might help Harry understand the more complex magical aspects related to his broomstick. For example, she could research ancient spells that were once used to enhance broomstick speed and try to apply them to Harry's broom.
One common theme is self - discovery. Harry, upon finding his family, learns more about himself, his heritage, and his potential. Another theme is the power of family bonds. These fanfictions often show how having a family gives Harry more strength and support in the face of the many challenges in the wizarding world. For example, in some stories, his newfound family members teach him new spells or magic that he can use against his enemies. Also, redemption can be a theme. If his family has a dark past, they might seek redemption through helping Harry and being part of his life.
Dumbledore may make an appearance in some fanfictions, even if it's just in flashbacks or as a guiding spirit for Harry and Hermione's family. His wisdom could be passed down through stories to their children. Also, characters like Hagrid might be involved, bringing his love for magical creatures into the family's life, maybe teaching the kids about how to care for them.
Snape could also be a central figure. Maybe he discovers Harry's situation early on and has a change of heart. He could secretly guide Harry, teaching him things about magic and the wizarding world that he otherwise wouldn't know, all while still maintaining his aloof exterior.
Harry Potter himself is often a central character. He might be exploring the vaults in search of something that could help him defeat Voldemort once and for all, like a powerful weapon or a spellbook.
Neville Longbottom is a common character in 'Harry Potter inheritance fanfiction'. Given his family's important place in the wizarding world and their losses, he could inherit something significant, like a powerful magical plant - related ability that was once held by his family. Draco Malfoy is another one. He might inherit some dark family secrets or a powerful magical object from the Malfoy family vaults, which could lead to all sorts of interesting storylines as he grapples with his family's legacy.