Hermione is often a key character. She might stand by Harry's side, using her intelligence and loyalty to help him through the tough times. She could be the one to encourage him to keep going and not let the disownment break him.
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.
Hermione is often a common character. Since she is Harry's closest friend, she usually plays an important role in helping Harry navigate the past. She might use her vast knowledge of magic and history to figure out why Harry was summoned and what they need to do next.
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.
Voldemort is often a key character. Since Harry is going dark, Voldemort might play a role in either guiding him into darkness or being an antagonist to his newfound dark power. Another common character is Hermione. She might try to save Harry from the dark path he's on, leading to a lot of conflict between them.
The dragon, of course, is a major character. It could be named something unique like 'Fyrstorm'. There might also be Hermione and Ron. Hermione would probably be worried about the legality and danger of raising a dragon, while Ron might be both scared and a bit excited about it.
Hermione would surely be involved. She could be Harry's research partner, helping him find relevant medical information in books and scrolls. Her intelligence and thirst for knowledge would be very useful in exploring new areas of medical magic. Another character could be Madam Pomfrey. She could be Harry's mentor, teaching him the basics of wizarding medicine and guiding him in his new role as a medic.
Hermione and Ron are usually quite common. Since they are Harry's best friends, they would be involved in the story when Harry's parents return. They might be curious about his parents, and also help Harry and his parents adjust to the current situation.
Hermione Granger is a very common character. Since she is Harry's best friend, she would likely be there to help him understand and control his new superpowers. She might research in the library to find out how these powers came about and how to use them effectively. Ron Weasley is also common. He would probably be both in awe and a bit jealous of Harry's new powers at first but would still support him in the end.
Hermione could be a main character. She would probably be very involved in helping Harry with the baby, using her vast knowledge of magic to ensure the baby's well - being.
The supreme Mugwump himself could be a main character. He might have his own backstory, motives, and goals that drive the story forward.