Definitely Harry Potter himself. He's the central character in his own series, so it's likely he'd be involved in any crossover. Hermione Granger could also be a key character as she's smart and curious, and would be interested in learning about the 'Twilight' world. From 'Twilight', Edward Cullen is an obvious choice. His brooding nature and unique abilities would make for interesting interactions with the 'Harry Potter' characters. Also, Jacob Black could be involved, especially when it comes to the 'imprint' aspect as he has his own story arc related to that in 'Twilight'.
In this kind of fanfiction, Severus Snape could be an interesting character to be involved. His complex personality and his knowledge of the dark arts in 'Harry Potter' could lead to some intense interactions with the vampires in 'Twilight'. From 'Twilight', Bella Swan could be included. Her connection to both the vampire and werewolf worlds in her own story could translate well into the crossover. And then there's Ginny Weasley. She's brave and strong - willed, and could potentially have some interesting relationships with the 'Twilight' characters, especially when considering the 'imprint' concept.
One interesting concept could be the combination of magic systems. In a crossover, the magic from 'Harry Potter' like spells and potions could interact with the unique vampire and werewolf abilities in 'Twilight'. For example, a wizard might try to create a spell to counteract the vampire's allure or a werewolf's enhanced strength. Another concept could be the cultural clash between the two universes. The Hogwarts students' way of life, with their houses and classes, would be very different from the social structures in 'Twilight'. And the idea of imprinting from 'Twilight' might be applied in a new way within the 'Harry Potter' world, perhaps a magical bond similar to imprinting could form between characters.
Definitely Edward would be one of the likely characters. His intense love for Bella in the original series could easily be translated into an imprint situation. Jacob is also a strong contender as he has his own deep connection with Bella. Additionally, if we consider other supernatural beings from the Twilight universe, perhaps a Volturi member could be involved. The Volturi are known for their power and mystery, and if one of them were to imprint on Bella along with either Edward or Jacob, it would create a very interesting power dynamic. There could also be a new werewolf pack member that Bella meets and who imprints on her along with someone else.
Voldemort would also be a key character. His obsession with immortality and his actions that led to many deaths in the series are fundamental to the theme of life and death. In a crossover, he could be pitted against new threats or forces that have different views on death, which would make for an interesting story.
Obviously, Harry Potter himself is the central character as the one being abused and neglected. The Dursleys are also key characters as they are the ones who abuse and neglect him in the original story. Hermione and Ron might also be involved as they could be the ones to discover Harry's situation and try to help him. Dumbledore could also be a part of it, perhaps as someone who failed to notice or prevent Harry's abuse initially.
Obviously, Harry Potter himself. Hermione would probably be by his side, helping him research about his claim to lordship, using her vast knowledge from the library. Ron might also be there, providing moral support and his unique sense of humor in difficult situations.
Neville Longbottom could be a key character. He might take on a bigger role in Hogwarts in Harry's absence and also be in touch with Harry, providing support from the school. Ginny Weasley would also be involved as she has a close relationship with Harry. Additionally, some of the Hogwarts professors like Professor McGonagall could play important parts, either trying to bring Harry back or helping him in his mission outside the school.
Obviously, Harry Potter himself is the central figure. His friends like Ron and Hermione would also be involved. They would support Harry in his revenge plans, with Ron providing his loyalty and Hermione using her intelligence to strategize. Ginny Weasley might also be part of it, as she is Harry's love interest and a strong - willed witch in her own right.
Harry Potter himself is obviously a central character as the focus of the so - called 'harem'. Hermione Granger could be one of the likely characters involved. She is Harry's close friend in the original series and her intelligence and magical abilities would make her a strong contender in any relationship - based competition. Ginny Weasley is also a likely character, as she has a romantic relationship with Harry in the official story. Luna Lovegood might be included too, with her unique personality and magical insights.
Obviously, Harry himself is the central character. Then there could be his friends like Hermione and Ron. Hermione might help Harry manage his fortune in a smart way, like investing in magical books or rare potion ingredients. Ron could be the one who gives Harry more down - to - earth advice on how not to let the fortune change him.
Snape is a likely candidate. In the original series, his loyalties were always a bit of a mystery at first. In fanfiction, he could be further explored in terms of false betrayals or real ones. Another one could be Draco Malfoy. He was on the verge of becoming a full - blown Death Eater in the original, so in fanfiction, he could either truly betray his Hogwarts classmates or be wrongly accused of betrayal.