Friendship is also a big theme. Just like in the original works, in the fanfiction, the characters form strong bonds. For example, in many crossovers, the students from 'Assassination Classroom' and the characters from 'Harry Potter' learn to trust and rely on each other. They support each other through difficult times, whether it's dealing with a dangerous magical creature or trying to assassinate Korosensei. It shows how powerful friendship can be in these fictional universes.
Nagisa Shiota from 'Assassination Classroom' can also be quite popular in these crossovers. He has his own growth arc in the original series. In a fanfic with Harry, he could learn from Harry's experiences at Hogwarts and vice versa. Their friendship could develop in a way that combines the best of both worlds, with Nagisa's assassination skills and Harry's magical knowledge.
Some fanfictions might explore the concept of different teaching styles. In 'Assassination Classroom', the teacher is very unconventional. So in a fanfic with Harry, it could be about how the Hogwarts teachers would react to this new style of teaching and how the students like Harry would adapt to it.
Sure. One popular 'Assassination Classroom' and 'Harry Potter' crossover fanfiction is 'The Transfer Student from Hogwarts in Assassination Classroom'. It combines the unique elements of both worlds in an interesting way.
There could be a crossover where some of the characters from Harry Potter end up in the Assassination Classroom. Harry, Hermione, and Ron might find themselves in the classroom, and they'd bring their own set of skills and knowledge. Hermione would probably be very interested in Koro - sensei's unique biology and try to figure out how to use magic to defeat him based on that knowledge.
One possible fanfiction could be about Nagisa, as a girl, having to deal with the unique challenges in the Assassination Classroom. Maybe she uses her newfound femininity to her advantage in different assassination attempts. For example, she could play on the stereotypes that others might have of a girl being less of a threat, only to surprise her opponents.
One possible fanfiction could be about female Karma's journey in the Assassination Classroom. Maybe she uses her intelligence and unique skills to outwit the other students in various assassination attempts. For example, she could come up with creative plans to get close to Koro - sensei while still maintaining her cool and mysterious demeanor.
One characteristic is the exploration of the unique characters. Fanfictions often dig deeper into the backstories and personalities of the students and the teacher in 'Assassination Classroom'. For example, they might expand on how Nagisa came to be so calm and observant. Another aspect is the different plot twists. Some fanfictions create alternate scenarios where the assassination attempts take on new forms or have different outcomes.
The magic system in Harry Potter could completely change the dynamics of assassination attempts in the Assassination Classroom. For example, invisibility cloaks could make it much easier for students to get close to Koro - sensei undetected. This would make the assassinations more likely to succeed, but also less of a challenge in some ways.