Sure! TBH, I’ll admit that I wasn’t the hugest fan of the ending–I think it fits thematically but I wanted him to live, but he didn’t and it wasn’t poorly written. I was just sad. Lol.

Korosensei had to die because the world refused to allow him to live. The entire last arc was people trying to make it so that he could live, but the world refused to let him. It was wrong, and i do think the narrative was clear that it should not have to happen, but people had hardened their hearts. Korosensei’s dilemma was kind of a metaphor for how the students were treated the entire story. They were kids, they fact that they acted out didn’t doom them but society was writing them off anyways, relegating them to legitimately a separate classroom in the woods. Korosensei had a very very very small chance of destroying the world–it was incredibly unlikely, but fear of what might happen drove the people outside to want him dead. Of course it’s understandable since the risk, while small, was really consequential should it happen. 

But the message is that society essentially writes people off before they should be. Yet at the same time, Korosensei’s last year was spent dismantling that, and his whole existence was a dismantling of that. He lived as if people had worth no matter what they had to offer the world, and that their usefulness did not determine their worth. So in the end, even though Korosensei had to die, when we see Nagisa growing up to be a teacher himself and presumably carrying on Korosensei’s legacy, we know that Korosensei’s death did not continue the system that killed him but in fact helped give the kids the beliefs and strengths they would need to slowly change things. Because all it takes is one person to convince someone they matter just because they exist, and that belief–that’s enough to change a life.