Assassin's Heart (HxH and Assassination Classroom crossover)

I do not own the Hunter x Hunter and Assassination Classroom. Gon, Killua, Kurapika, Leorio, and Alluka(Nanika) get transferred to another world. They met Mr. Karasuma. He invites them to the government official's room asking them to kill an octopus who is teaching class E and who will destroy the world next year. (Th...