Another instance could be Hermione betraying Harry in fanfiction. Suppose she falls in love with someone who is against Harry, like a pure - blood supremacist in a different version of the wizarding world. Her love for this person makes her go against Harry, which is a huge betrayal considering their close friendship in the original story.
I'm not sure of specific examples off the top of my head. But in general, in such fanfiction, it might involve Harry being betrayed by those in his so - called harem, perhaps by lies or broken trust. For instance, a character he trusted might turn out to be working for the dark side and use their relationship to get information on him.
I'm not sure specifically which 'Harry Potter betrayed' slash fanfictions exist. But in general, a 'betrayed' theme might involve a character like Harry being betrayed by a close friend, perhaps Ron or Hermione in some dark, alternate storyline created by the fanfic writer. It could explore themes of broken trust and how Harry copes with such a betrayal.
One example could be 'The Broken Trust'. In this fanfiction, Fem Harry Potter discovers that her closest friends have been hiding secrets from her that make her feel betrayed. Another might be 'Shadows of Deception' where the magical world turns against her in a cruel way. And 'Forsaken by Allies' shows how Fem Harry is left alone after being betrayed by those she thought she could rely on.
There's a fanfic called 'False Alliances'. After the war, Potter discovers that some of the people he worked with during the war had ulterior motives. They betray him to gain control over certain dark magic artifacts that Potter was protecting. It shows how the after - effects of war can create a climate of mistrust and betrayal.
One common theme is the shattering of trust. For example, when a close friend like Hermione or Ron betrays Harry, it shows how fragile trust can be in the face of various temptations or misunderstandings. Another theme is isolation. After being betrayed, Harry often finds himself alone, having to rely on his own strength, which is a big part of these fanfictions.
In some 'percy betrayed' fanfictions, Percy might be betrayed by his friends. For example, they could believe false rumors about him and turn their backs on him. This could lead to Percy feeling isolated and having to fend for himself, often resulting in him finding new allies or uncovering secrets that change the way he views his old friends.
Well, in some nightmare fanfictions, Harry Potter might find out that his parents were actually evil all along. This completely changes his view of himself and his place in the wizarding world. Another example could be a fanfic where the magical world is slowly being destroyed by a mysterious force and the characters are powerless to stop it. It creates a very dark and hopeless atmosphere for the story.
One example could be a fanfiction where a character acts completely out of character in a cruel way towards others, like Harry Potter suddenly turning on his friends without any real motivation. Another might be a story that twists the original themes of love and friendship in the series into something cold and unfeeling.
One example could be a fanfiction where Harry Potter visits an Indian wizarding school that has its own unique houses based on Indian values like Dharma, Karma, etc. Another could be a story where Hermione has an Indian heritage and uses Indian magic spells along with the regular ones from the original series.
Fanfiction involving drugs is not in line with the positive values of the original 'Harry Potter' series, and I don't recommend seeking or promoting such content. J.K. Rowling created a magical world full of positive values like friendship, courage and justice, and we should focus on fan works that adhere to these values.