The themes include growth and transformation. The students start off as rather ordinary kids, but through their interactions with Koro - sensei and the challenges of the assassination plot, they grow in many ways. There's also the theme of acceptance. They come to accept Koro - sensei for who he is, even as they are still tasked with killing him. And there's a sense of hope throughout the light novel, that no matter how difficult the situation, things can get better.
Koro - sensei is definitely one of the most interesting characters. He's an octopus - like alien who is supposed to destroy the Earth but instead becomes a teacher. His superhuman abilities and his unique teaching methods make him stand out. Nagisa Shiota is also interesting. He has an unassuming appearance but is very perceptive and has some great assassination skills.
One of the main themes is growth. The students in the story experience significant personal growth throughout their time with the teacher. Another theme is the value of education, as the 'assassination' lessons are also a form of unique education. And there is also the theme of friendship that develops among the students as they face challenges together.
The 'Assassination Classroom' is about a powerful octopus - like creature that destroys a large part of the moon and threatens to do the same to Earth. He becomes a teacher of a class of misfit students. The students are tasked with assassinating him within a year. As the story progresses, the students grow both in their assassination skills and as individuals. They form bonds with their strange teacher, who also teaches them valuable academic and life lessons.
One of the main science fiction elements in 'Assassination Classroom' is the character of Koro - sensei. He is an octopus - like being with extraordinary powers, which is a very imaginative and science - fictional concept.
Itona in the Assassination Classroom fanfic is often depicted as a complex character. He has his own unique backstory and growth arc. His relationship with other characters, like Nagisa and Karma, can be explored in different ways in fanfics. Sometimes he is shown as a more vulnerable side, which is different from his tough exterior in the original anime.