The introduction of Irina Jelavich was interesting because you add an assassin to the fold. Granted, she can’t do much against Koro-sensei. The funny part is them preferring Koro-sensei because the students main motivation is killing him, so if he is not present, what is the point? Though the most interesting is how the situation played in favor of Koro-sensei.
Though the big roadblock for Koro-sensei is the principal, Gakuho Asano. As for the structure he made for the school, he essentially made the students not want to fall to class 3-E. As we know, there are so many disadvantages to being in that class. Even in theory you could transfer out; that seems to never happen due to a loss of motivation.
For someone like Koro-sensei, who cares for his students, he doesn’t want them to give up on them. Still, as strong as he is, standing up to the principal is a different battle. I’m curious when final exams come around because the level field will not be fair. It’s also nice seeing Koro-sensei winning over Karma.
As the school trip happens, we see in Nagisa’s group both Kaede and Yukino Kanzaki get kidnapped. More than likely we will learn more about who Yukino really is. Given that the book had instructions for a kidnapping, it does seem that we could see the guys being able to save the girls.