Well, usually these fanfics focus on the character development of the brother and his relationship with Harry. There might also be new magical adventures and challenges for them to face together.
Often, such fanfics explore the brother's unique magical abilities and how they compare to Harry's. It could also delve into family dynamics and the impact of being in Harry's shadow.
One interesting plotline could be the brothers having a secret mission within Hogwarts that the original books didn't cover. For example, they might be on a quest to find a hidden magical artifact that has been lost for centuries. Another could be their relationship dynamic affecting the course of major events in the wizarding world, like how they interact with Harry and his friends during the Triwizard Tournament.
The exploration of her identity is a major element. As a female Harry, she might question her role in the prophecy more deeply. Does being female change what it means to be the Chosen One? Her relationships with female characters like Ginny could also be more in - depth, with shared experiences and mutual support. And the way she is perceived by the wizarding society at large would be a significant part of the fanfic.
One possible plotline could be that Harry discovers he has a half - brother he never knew about. Maybe his father had a relationship before he met Harry's mother, and this new character enters Harry's life. They initially have some conflicts due to jealousy or differences in upbringing, but over time, they come to love and support each other.
One possible plotline could be that they discover their relation later in life. Harry, being used to the magical world, is shocked to find out he has a brother in a completely different scientific realm. And Bruce has to come to terms with having a wizard for a brother. They then start to learn from each other's worlds, with Harry showing Bruce some basic magic and Bruce trying to explain his scientific research to Harry.
One plotline could be that they discover their relation later in life. Harry, having grown up in the wizarding world, and Superman, in his superhero world, suddenly find out they are brothers. They then have to combine their powers and knowledge to face a common enemy that threatens both their worlds, like a powerful dark wizard who has also got hold of some kryptonite - like substance.
It's rare. Usually, the 'boy who lived' is Harry Potter himself in the original story and most fanfictions adhere to this. However, there could be unique takes where his brother takes on that role, but it's not the norm.
Well, some fanfictions might focus on alternate timelines where Harry makes different choices. Others could involve him facing new magical threats or forming unexpected alliances.
One possible plotline could be that the older brother is a prodigy at magic and overshadows Harry in the beginning. For example, he might be the top of his class in every subject at Hogwarts. This could create some jealousy or a sense of inadequacy in Harry at first. But as the story progresses, they could learn to support each other and the older brother could use his skills to help Harry in his battles against Voldemort.
Well, usually they involve intense emotions and a means of communication that causes a big scene. Howlers often convey strong feelings like anger or worry.
In the 'Harry Potter, You're a Naughty Boy' fanfiction, there could be a plot where Harry is constantly getting into trouble for using magic outside of school during the holidays. He might be using it to play tricks on Dudley and his gang, like making Dudley's pants fall down in public every time he tries to bully someone. This would be a different side of Harry as we usually see him being more reserved when it comes to using magic around Muggles in the original series. And it could lead to some interesting interactions with the Ministry of Magic as they try to keep an eye on this 'naughty' Harry.