There could also be new characters introduced in the fanfic. Maybe a young, talented wizard or witch who is just starting at Hogwarts and becomes involved in Harry's return journey. They could bring a fresh perspective and new abilities to the story. And of course, Dumbledore, even if he's not physically present all the time, his influence and legacy are likely to play a role, so he can be considered one of the important characters in a sense.
It could be the descendants of the original Harry Potter characters. Maybe a son or daughter of Harry and Ginny, for example.
Obviously, Harry Potter himself would be one of the main characters. He's always at the center of things at Hogwarts. Hermione Granger would also be a main character as she is Harry's friend and is very intelligent, she would be trying to solve the problems during the lockdown. Ron Weasley too, as he's part of the trio. And of course, Professor Dumbledore, who would be in charge of handling the lockdown situation and making decisions for the safety of the students and the school.
Obviously, the four founders - Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw, and Salazar Slytherin would be main characters as they are the ones returning.
Hermione Granger would likely be a main character. She could use her vast knowledge to help Harry in his efforts to fix Hogwarts, whether it's researching ancient spells for repairs or coming up with new educational strategies.
It could also include some new characters created specifically for the fanfiction. Maybe a young wizard or witch from a minor house who plays a crucial role in uniting Hogwarts. They could have some special abilities or a unique backstory that helps in bringing the students together.
The heir themselves would be a main character, of course. And Harry Potter might still play a role, either as a friend or a rival to the heir. Dumbledore could also be a major character, guiding or observing the heir's journey.
Other main characters could include the ward's new friends at Hogwarts. They could be from different houses and have different personalities. Together, they form a group that helps the ward through various adventures, whether it's exploring the Forbidden Forest or uncovering secrets within the castle walls.
Most likely, the Hogwarts Four would consist of Harry Potter, who is known for his courage and his connection to Voldemort. Hermione Granger, with her vast knowledge of magic and quick thinking. Ron Weasley, who brings loyalty and a sense of humor to the group. And it could be Luna Lovegood as the fourth member. Luna has her own unique perspective on the wizarding world and could add a different flavor to their adventures.
Obviously, Harry Potter is the main character. He is the one taking on the role of the guardian. Hermione and Ron usually play important supporting roles as well. They help Harry in his mission to protect Hogwarts with their knowledge and skills.
Obviously, Harry Potter himself would be a central character. Ron and Hermione, his closest friends, would also likely be in it. Ginny, as Harry's love interest, would probably play a significant role too. Other characters like Neville, who has grown into a strong wizard, could also be featured. And of course, we might see some of the old Hogwarts professors, perhaps McGonagall still guiding the school in some way.