However, Deku has always had incredible intellect and thus has become a teacher at UA High School alongside Aizawa Shouta, although Aizawa wishes Deku would be stricter with his students.

My Hero Academia Chapter 420 reveals that before Shota Aizawa warped to Deku’s side in the previous chapter, Eri actually broke off her horn and gave it to Aizawa to help Deku.

Aizawa's teaching philosophy stemmed from his trauma and loss of his best friend, Shirakumo. Shirakumo's death greatly affected Aizawa, leading him to isolate himself and become an underground hero.

My Hero Academia has reached a new turning point in the final war against the villains, and the newest chapter of the manga has set up Shota Aizawa’s plan to help bring it all to an end! My Hero ...

Back in the fight, Aizawa stabs Deku with Eri’s horn which will take a few minutes to heal him since she was low on energy. Aizawa tells Deku he can’t die until he gets to hear Eri sing.