One possible plotline could be that Harry is influenced by a dark artifact. For example, he discovers a cursed object that slowly corrupts his mind, making him turn against his friends. He might start to use dark magic to achieve his goals, believing that the end justifies the means.
In some 'Harry Turns Dark' fanfictions, Harry could be betrayed by the wizarding world he once trusted. This betrayal, like being wrongly accused of a crime he didn't commit, could lead him to embrace the dark side. He then uses his knowledge of both light and dark magic to take revenge on those who wronged him.
Another plotline might involve Harry being manipulated by a powerful dark wizard. This dark wizard could be Voldemort in a different form or a completely new character. They use mind - control spells or false promises to turn Harry dark. Harry then becomes a force to be reckoned with, using his newfound dark powers to try and reshape the wizarding world according to the dark wizard's plan.
One possible plotline could be Rey being influenced by a powerful dark side artifact. Maybe she discovers an ancient Sith relic that slowly corrupts her mind and turns her to the dark side. She starts to have different views on power and the Force, believing that the ends justify the means.
One possible plotline could be Harry struggling to control his new veela - like charm powers and accidentally causing chaos at Hogwarts. For example, he might make his classmates act strangely around him, much to the confusion of his friends.
A great plotline could be that Harry, now a girl, has to navigate the world of wizarding fashion and etiquette which she previously ignored. She might be forced to attend more social events at Hogwarts, like balls or tea parties, where she has to learn proper behavior. And she could also use her new identity to her advantage when it comes to spying on the Death Eaters. They might underestimate her because she's a girl, but she could outwit them.
In some 'Harry Potter turns into Hermione fanfiction', the plot may involve Harry adjusting to Hermione's physical appearance as well. He might be shocked at first but then realizes the advantages it gives him. For example, he could use Hermione's reputation for being a bookworm to his advantage when it comes to researching dark magic or hidden secrets in the library. And he may also face some difficulties when it comes to Hermione's friendships with other girls, as he has to act like her and keep those relationships intact.
One possible plotline could be Harry struggling to control his new vampire instincts while still trying to protect his friends at Hogwarts. He might have to deal with the thirst for blood while attending classes and facing off against the Dark Arts. Another could be that he discovers a whole new vampire community within the wizarding world that has its own rules and power structures.
One popular 'Harry Turns Dark' fanfic could be 'The Darkened Heir'. In this type of fanfic, often the author explores how Harry's experiences could have pushed him towards the dark side. Maybe the betrayal he faced from some in the wizarding world made him bitter. Another could be 'Dark Harry's Ascent' where the story might show how Harry uses dark magic to get revenge on his enemies. And there's also 'Harry: The Dark Lord Reborn' which could play with the idea of Harry taking on a more sinister role similar to Voldemort but with his own motives.
Another plotline could involve a betrayal within the group that causes Elsword to turn dark. For example, if he discovers that one of his closest allies has been secretly working against him all along, the shock and anger could drive him to the dark side. He might then start to seek revenge on not only the betrayer but also those he perceives as being part of the conspiracy.
One possible plotline could be Ginny being influenced by a dark magical object that makes her turn against Harry. This could lead to a series of conflicts as Harry tries to figure out what's wrong with her and how to save her. Another plotline might involve Harry and Ginny being caught in a dark prophecy that forces them to make difficult choices that seem against their nature. For example, they might have to choose between saving each other or the wizarding world.
In this fanfic, it could be that Harry turns into a snake as a result of a powerful transfiguration spell gone wrong. As a snake, he has to navigate the Hogwarts grounds in a new way. He might find secret passages or areas that are only accessible in his snake form. His friends, like Hermione and Ron, would then try to find a way to reverse the spell, and there could be a lot of trial and error, as well as some really heart - warming moments of friendship along the way.
One idea could be that Harry discovers a dark secret about his family that leads him down a dark path. For example, he might find out that his ancestors were involved in some really evil magic and he starts to explore that side of magic. Another could be that the influence of Voldemort somehow remains and corrupts Harry's mind over time. Maybe the Horcrux inside him wasn't completely removed and it starts to change his way of thinking.