I was considering to watch the special screening 2 weeks ago and I am glad that I did not do that. Although I don't find the first movie to be fantastic, it is still quite good in the sense that it makes me looking forward to watch for the second part. Unfortunately, this becomes a good example of how a sequel movie basically butchers the series altogether. Whatever elements which retain my interest for the first movie is almost absent here and that's why I feel that this is an absolute trash.
We spend quite a lot of time with the background story of Koro-sensei. I guess it is meant to be something emotional but I find it too draggy as all the small talk between the God of Death and Yukimura-sensei seem to trivial to result in the kind of bond that both of them have. It is also revealed that because of the experiment, Koro-sensei will explode this March due to the chemical reactions going on inside him.
Coming back to the present, everything is worse. First we have the school festival that serves no purpose whatsover. A new character is introduced here to also target Koro-sensei but again his appearance and then disappearance really like no head no tail.
We also have class 3E divided between saving Koro-sensei and killing him after listening to his flashback. The conflict is resolved with a fight between Karma and Nagisa. There is nothing exciting about the fight and the fight also ends in a lame manner. The class eventually unites and decides to save Koro-sensei. At this point, things are getting even more ridiculous. With time running short, the world nations finally agrees to kill Koro-sensei by building a barrier around the school and getting ready to shoot a laser beam from outer space. Yeah.. if they can do that from the start, why aren't they doing that from the beginning? The student miraculously develops a 'cure' which is actually a ploy from Kotaro Yanagisawa, the real bad guy who uses Koro-sensei as his guinea pig. This 'cure' turns out to be something to weaken Koro-sensei so Kotaro can take his revenge. It is totally dumb that a scientist like Kotaro is unable to make this 'cure' and set up a plan so that the 'cure' is made by high school students.
I don't expect things can go worse from here but it does. In the end, Koro-sensei just asked his students to kill him. Wahahahaha.. What the fuck is going on here?? What's is the point of having the students trained and making 2 movies if in the end this yellow octopus-like creature decides to let himself be killed?
Humour, which is the saving grace for the first movie, is severely lacking here and that is a bummer. Once you are used to Koro-sensei, you will not find him funny anymore. Bitch-sensei has a much reduced screentime and is sorely missed as she is one main contributor of the crazy and funny scenes from the first movie.
With that, I don't think there is anything that makes this movie worth watching and well, I am glad that there will not be part 3.