One common theme is family loyalty. Despite being in different houses, the Slytherin brother often has a strong sense of loyalty to his family, especially to Harry. Another theme is the struggle against stereotypes. Slytherin is often seen as the 'evil' house, and the brother has to fight against this perception. For example, in many fanfictions, he proves that Slytherins can be just as brave and good - hearted as those in other houses.
The theme of self - discovery is also prevalent. The older Slytherin brother has to figure out who he is in the context of his house, his family, and the wizarding world. In some fanfictions, he may have to come to terms with his own dark side, like a tendency towards ambition that could cross into greed. Also, the relationship with other Slytherins and how it affects his view of himself is a big part of it.
Power and its corrupting influence can be a theme. As a Slytherin, he may be more exposed to the allure of power. Some fanfictions explore how he either resists or succumbs to this. There's also the theme of redemption. If he has made mistakes or been on the wrong path, he may seek redemption, especially in relation to his family and Harry. This can add a lot of depth to the character and the story.
One interesting fanfiction could be 'The Slytherin Legacy'. In this, Harry Potter's older Slytherin brother has to navigate the complex world of Hogwarts. He struggles with the family's expectations and the Slytherin house's reputation. Another one is 'Brother in the Shadows'. It shows how he tries to protect Harry from afar while dealing with his own dark desires that come with being a Slytherin.
One common theme is redemption. Slytherins are often seen as the 'bad guys' in the original series, so protecting Harry gives them a chance at redemption. For example, they might be trying to make up for past wrongs or the actions of other Slytherins.
One common theme is redemption. Harry often has to prove himself to the Slytherins who abuse him, and in the process, some of his abusers might see the error of their ways. Another theme is resilience. Harry endures the abuse and grows stronger from it, showing his Gryffindor - like courage even while in Slytherin.
One common theme is the exploration of hidden heritage. It often shows Harry finding out that he has a connection to Slytherin through his family tree. Another theme could be the struggle between the different values of Gryffindor (which Harry is known for) and Slytherin. For instance, Harry might have to reconcile his Gryffindor courage with Slytherin's cunning.
One common theme is family loyalty. The Slytherin sister often has to balance her loyalty to her family, which may have strong Slytherin values, with her own moral compass. For example, she might have to decide whether to side with her family's traditional views or stand up for what she believes is right, like equality among all the Hogwarts houses.
One common theme is identity struggle. Harry has to grapple with being associated with Slytherin, a house known for its darker tendencies, while being a Gryffindor. Another theme is the exploration of Slytherin's past and its secrets. Writers often dig into the history of the house, its founders, and the magic associated with it. There's also the theme of friendship and acceptance, as Harry's friends have to come to terms with his new identity.
Another theme is loyalty within Slytherin house. Some fanfictions explore how Slytherins can be loyal to their own, even in the face of external challenges or when their actions seem at odds with the general Hogwarts population. It often shows a complex web of relationships within the house. For example, a Slytherin might be loyal to a friend who has been ostracized by the other houses. Also, power and ambition are often themes. Since Slytherin values these traits, fanfictions might explore how characters use their ambition in different ways, whether it's for personal gain or for the greater good of the wizarding world. This can lead to interesting character arcs where a Slytherin has to make difficult choices between their own desires and what is right for the community.
One common theme is the struggle against the negative stereotypes associated with Slytherin. Female characters often have to prove themselves as not being purely evil just because they are in Slytherin.
One common theme is the exploration of his dark side. Since he was known for his ideas on pure - blood supremacy, many fanfictions delve into his motives and how that ideology developed. Another theme is his relationship with the other founders. Some stories focus on the initial harmony and then the growing rift between them.
Love and jealousy are also common themes. With multiple characters in a harem, there is bound to be love triangles or more complex relationship webs. Jealousy can arise when one character feels that another is getting more attention or has a stronger connection to the central character, leading to interesting plot developments and character growth.