One common theme is the crossover of identities. Kpop idols are given new identities as wizards or witches in the Harry Potter universe. Another theme is the use of kpop group dynamics in the magical world. For instance, how a group's teamwork in kpop can translate to solving magical quests at Hogwarts.
Often, there is a theme of friendship and teamwork. Just like in Harry Potter, where Harry, Ron and Hermione work together, in these fanfictions, Kpop group members or different idols collaborate to overcome challenges in the wizarding world. For example, they might team up to defeat a dark wizard who threatens both the Kpop and magical worlds.
There's 'The Kpop - Harry Potter Crossover'. In this fanfiction, the world of kpop collides with the wizarding world. Some kpop groups are depicted as having magical powers related to their stage personas. It's a really fun read as it combines the glitz and glamour of kpop with the mystery of Harry Potter.
A great one is 'Hogwarts School of Kpop'. This fanfiction reimagines Hogwarts as a school for Kpop trainees. The houses are based on different Kpop concepts like cute, cool, etc. The trainees learn not only magic spells but also how to perfect their Kpop performances. It's a very creative take on combining the two universes.
He could be shocked. Maybe there are some fanfictions that take a very dark turn or have unexpected pairings that he never thought of. He'd probably need some time to process such strange ideas. And he might also be curious to see how far the creativity of the fans can go. He might even get some new ideas about his own life from reading some of the more imaginative fanfictions.
He may be confused at first. Fanfics can be very different from his real experiences. He might wonder why people write such things about him and his world.
Well, Harry Potter is a rather humble character. He might initially feel a bit embarrassed to see himself as the center of so many fictional stories created by fans. If the fanfic portrays him as a hero in new adventures, he would probably be honored. However, if it misrepresents his friends or the values he holds dear, he could be a bit indignant. He would likely approach it with an open mind but also with a sense of protectiveness towards his own story and those he loves.
Harry might initially be shocked and confused. He's used to Hogwarts being his safe haven, so when it turns against him, he'll be at a loss. He may try to prove his innocence by finding evidence or confronting those who are spreading lies.
The headmaster might be a bit surprised at first. He would likely respect Harry's opinion, though. He has always valued Harry's thoughts and feelings. He may start to think about the implications of fanfiction on the wizarding community and how it might affect the students and the overall perception of Hogwarts.
As time goes on, Harry could start to explore what it means to 'please' Sirius. He might recall their past relationship, the things Sirius likes and dislikes, and try to use that knowledge to his advantage. He may also feel a sense of loyalty towards Sirius that, despite the odd circumstances, makes him more accepting of the situation. For example, he might remember Sirius' love for adventure and try to engage in some magical adventures with him in a way that 'pleases' him.