Assassination Classroom, Volume 20 (Assassination Classroom #170-177)

The battle for Koro Sensei's life against a multinational operation's soldiers and weaponry is difficult enough, but now his creator, mad scientist Yanagisawa, and and his former protégé, Grim Reaper II, join the battle to destroy him - and they've both had major enhancements! But the stakes abruptly change when a 3-E student is fatally caught in the crossfire... If there's one thing that enrages 3-E's teacher, it's harming - let alone killing - his students! Koro Sensei's fury and ingenuity know no bounds, even as fate inexorably catches up to him...