Voldemort could also play an important role. Since Harry is now the dark prince, there could be a complex relationship between them. Voldemort might see Harry as a potential ally or a threat, and their interactions would surely be a major aspect of the fanfiction, along with how Harry navigates this new relationship with the most feared dark wizard.
Well, obviously the Dark Prince himself is a main character. He's likely to be a complex figure with his own motives and desires. Then there could be his friends or followers, who might be other dark wizards or witches that support his cause.
The main characters would include the Dark Prince himself. Then, we might see characters from the original series like Neville Longbottom having a more prominent role in this fanfic. Maybe he becomes one of the key resistance fighters against the Dark Prince. And there could be some new characters introduced, like a mysterious wizard from a far - off land who has some knowledge about the Dark Prince's true nature and comes to Hogwarts to help in the fight against him.
In this fanfiction, the main characters could be quite diverse. Since it's about a 'dark heir', there would likely be a character who embodies this role. It could be a previously unheard - of character with a complex backstory related to a dark legacy. Harry Potter might be involved to oppose this dark heir or to try and understand their motives. His friends, like Hermione and Ron, could also be part of the story. Additionally, there could be other magical beings or characters from the 'Harry Potter' lore, such as members of the Order of the Phoenix or Death Eaters, who are drawn into the plot due to the emergence of the dark heir.
Obviously, the Dark One is a main character. Harry Potter himself also often plays a crucial role as he is usually the one who has to face the Dark One in some way.
Well, Harry Potter is most likely one of the main characters as it's a Harry Potter fanfiction. He would probably be at the center of the new revelations and story developments.
It's possible that the main character is the 'dark child' of course. There could also be a mentor - like figure, maybe an older wizard who tries to guide the child towards the light. And it wouldn't be surprising if there were some antagonists as well, such as other dark wizards who want to use the child's power for their own evil purposes.
There could also be an original character created specifically for this fanfiction who becomes the Dark Phoenix. This character would then be a central focus, with their transformation and the resulting events driving the story forward. Their backstory, motives, and relationships with other characters would be important aspects of the narrative.
There could be some disillusioned wizards who have lost faith in the current state of the wizarding world. They might see the Dark Prince as a way to change things, even if his methods are dark. These wizards could be those who have been marginalized or have suffered losses during the war. They believe that the Dark Prince has a vision for a different kind of wizarding society, not realizing the full extent of his dark intentions.
In this fanfiction, the Dark Prince might find allies among those who have been wronged by the Ministry of Magic. If there are wizards who have been unjustly punished or whose families have been persecuted, they could be swayed to join the Dark Prince. There could also be some international dark wizards who see an opportunity to expand their influence in the British wizarding world through an alliance with the Dark Prince. Another possibility is that there are some dark entities from other dimensions or realms that the Dark Prince manages to summon and convince to be his allies.
The Slytherin Prince is, of course, central. Then there might be characters like Draco Malfoy, who could be either a friend or a rival to the Slytherin Prince. Hermione Granger could also be involved, as she often crosses paths with different characters in fanfictions. Additionally, there could be original characters created specifically for this fanfiction, perhaps a long - lost relative of the Slytherin Prince who has some secrets to share.