Another plotline could be that Harry discovers a hidden side of the wizarding world that is far more cruel and power - hungry than he ever imagined. His ruthlessness develops as he has to fight against this hidden establishment. He might start by trying to work within the system, but when he realizes the system is corrupt, he decides to take matters into his own hands, making him a maverick in the wizarding world, feared by some and revered by others.
One possible plotline could be Harry using his ruthlessness to take on the dark forces in the wizarding world more directly. For example, he might not hesitate to use more extreme magic against Voldemort's followers, without waiting for the Ministry's approval or following the traditional rules of combat.
Perhaps in this fanfiction, Harry's ruthlessness is a result of some great betrayal. He could be betrayed by someone close to him, like a friend from Hogwarts, and this turns him into a more cut - throat character. He then uses his new - found attitude to seek revenge and also to reshape the wizarding world according to his own vision of justice, which may be quite different from what the established wizarding society believes in.
One possible interesting plotline could be Harry's interactions with the Greengrass family. Maybe he forms an unexpected friendship with Daphne Greengrass and through her, gets involved in the complex politics of the pure - blood families in the wizarding world.
One possible plotline could be how Harry's dictatorial rule affects the wizarding society. Maybe he starts imposing strict laws on magic use, which could lead to a rebellion by some wizards who value freedom.
One interesting plotline could be Harry's journey to master different sword techniques. Maybe he discovers ancient sword-fighting styles and has to train hard to master them, facing challenges like difficult instructors or scarce resources.
Another plotline might involve Harry inheriting a hidden magical ability from an ancestor. He then has to learn how to control and master this new power while dealing with the challenges it brings, like the envy of some of his classmates and the interest of dark wizards.
One interesting plotline could be exploring Dumbledore's younger years through Harry's eyes. Maybe Harry discovers some old memories of Dumbledore's adventures as a young wizard, and it helps him understand Dumbledore better. This could also show how Dumbledore's past experiences shaped his decisions in dealing with Harry and the fight against Voldemort.
One possible plotline could be Harry's struggle to control his new succubus powers. For example, he might have to deal with the sudden urge to feed on energy in inappropriate situations. Another could be how he hides his true nature from his friends at Hogwarts, like Hermione and Ron, while still trying to figure out what it means to be a succubus in the wizarding world.
In the fanfiction, Harry might be a gambler who bets on Quidditch matches. He could use his insider knowledge of the players and the teams to place bets. But then he gets into trouble when the wrong people find out about his gambling activities, and he has to find a way to fix the situation while still being true to his love for the sport.
One possible plotline could be Harry discovering his elf heritage and having to navigate the unique magical abilities and social status that come with it. For example, he might struggle with how the wizarding world views elves while also trying to embrace his new identity.
One interesting plotline could be Harry growing up in a completely different magical family and having to adjust to their unique traditions. For example, if he was adopted by a family of potion - makers, he'd have to learn their special techniques.
In certain 'harry is dead fanfiction' stories, a plotline could be the new generation of wizards rising up in the wake of Harry's death. His death could be a catalyst for change. Younger characters who were inspired by Harry might form a new resistance against any emerging threats. They would have to learn from Harry's example and find their own strength to protect the wizarding world.