Assassination Classroom: The Octopus & The God Killer (Harem X Male Reader)

The assassins meet serial killer.

This is for adult story nor for 13 or 15 year old.

A powerful creature claims that within a year, Earth will be destroyed by him, but he offers mankind a chance by becoming a homeroom teacher where he teaches his students about how to kill him. An assassination classroom begins. However that this creature had a clone and even more powerful than him and he was called 'Destroyer, King In Red, and Satan' that is exactly he was become the most dangerous powerful than Koro. The octopus had a clone son name is (Y/N) Korogane Yukimura AKA Carnage/The King In Red and he was been birth by his own mother since she was get killed by the government and however (Y/N) is become something worst for what the world gonna see how ruthless, brutal, and killing machine by himself...he's a serial killer who attempt to do his own justice with vengeance.

If the two of them meet each others and the two of them are going to fight each others like a death battle to see which one of them are the strongest. Will the students seen how the father and son are compare to each others? Are they gonna see the two of them that they were threaten to the government that they willing to destroy them all.