Ron Weasley can be there too. He could provide some comic relief and also be a friend to the new child. His loyalty and his family's unique place in the wizarding world can add interesting elements to the fanfiction.
Obviously, Harry Potter himself often makes an appearance. He could be a mentor or just a character that the new child of magic looks up to.
Often, Harry Potter himself is a common character. He might be exploring new aspects of water magic. Hermione is also likely to be involved as she loves to study and could be researching water - based spells. Ron could be there too, maybe a bit hesitant at first but getting into the adventure of water magic. And of course, there could be original characters created specifically for the fanfiction, like a young wizard from a family known for their water magic abilities who befriends Harry and the gang.
Neville Longbottom might be a key character in some fanfictions. He could be working closely with Harry in reforming the Herbology department or be involved in some sort of magical conservation efforts. Luna Lovegood could also be present, maybe running an alternative magical theory research department at the Ministry. And of course, some of the old Ministry employees like Kingsley Shacklebolt might still be around, helping Harry in his new role.
Harry Potter himself is often involved. Writers might explore how he could use the magic eye in different ways to solve mysteries or fight against the dark forces. Hermione would also be a common character. She could study the magic eye and try to understand its mechanics and magic better.
Hermione is often a common character. In these fanfictions, she might play a different role. For example, she could be the one to discover Harry's unique upbringing and help him understand how it makes him different from other wizards. Ron could also be there, and his friendship with Harry might develop in new ways. Maybe he's a bit more in awe of Harry's magic since he was raised by more powerful magic sources.
Well, Neville could be a significant character. He has come a long way since his Hogwarts days and could be a source of inspiration and support for the secret child. Ginny, as Harry's wife, is also very likely to be in these fanfictions. She could be a protective mother figure, or she might be involved in the decision to keep the child's identity a secret in the first place. And of course, there could be new characters created specifically for the fanfiction that interact with the secret child in various ways.
Harry Potter himself is often a central character in these fanfics. Since he has a history of facing great challenges, it's easy to imagine him being drawn into the world of forbidden magic, either by accident or because he feels it's necessary to defeat a new dark force.
Well, of course, Harry Potter is common. But you'll also find Dumbledore in many fanfics related to this. He could be guiding the main character in their journey with the sword and magic. There are also fan-created characters, like a powerful witch from a far - off land who comes to Hogwarts because of the rumors of the magical sword. These characters add new dynamics to the story.
Severus Snape is also a popular choice. His complex character and vast knowledge of magic can create interesting dynamics when he meets characters from different magical worlds. He could either be a mentor or an antagonist in these crossovers.
Obviously, Harry Potter himself is the central character. Then there are often the Dursleys, who would have to deal with Harry's early magic in different ways. Sometimes, Hagrid might also be involved earlier, coming to rescue Harry from the chaos caused by his early magic manifestations.
Besides Harry, Hermione is a key character. She can research and find loopholes in the Ministry's laws and regulations. Ron is there too, providing muscle and emotional support. Neville Longbottom could also be involved. He has grown into a strong and brave wizard, and he might join Harry's cause. Additionally, Luna Lovegood with her unique perspective on magic could offer different ways of approaching the conflict with the Ministry. Some fanfictions might also include Sirius Black, if set in a timeline where he didn't die, as he has a history of opposing the Ministry's unjust actions.