Why did All Might and Sir Nighteye Stop Working Together?

My Hero Academia’s universe is continuously expanding, leading to many big reveals in the latest season. With the introduction of All Might’s former sidekick, Sir Nighteye, the sour relationship between the duo and the nature of their relationship was kept hidden until recently.

Fans wondered why Sir Nighteye had refused to continue working under All Might, but it is now clear that his decision was correct. The fourth episode of the new season, titled “Fighting Fate”, gives us some insight to why the duo stopped working together. 

Sir Nighteye refused to work under All Might as he foresaw All Might’s death using his quirk. We find out more details about the topic when Midoriya confronts All Might about this revelation. In a flashback, All Might tells Midoriya how they had a falling out after One for All and All for One’s first clash. All Might was injured severely in the battle, and Sir Nighteye was against the idea of All Might continuing this work despite this.

All Might didn’t accept this and continued to act as the undeterred Symbol Of Peace for the world. He was worried that the world would fall into darkness with All for One still alive. Sir Nighteye insisted that One for All should be passed onto the next generation and All Might should take some well-deserved rest. Nevertheless, their partnership broke up because of the difference between their views.

Sir Nighteye had been working with All Might for 5 years and was taken under his wing because of the admiration Nighteye held for him. After Nighteye foresaw the death of the Symbol Of Peace viciously, he was firmly against All Might continuing his work, and this caused a break in their alliance. This explains All Might’s nervousness behind meeting Nighteye because he knows that Nighteye’s vision came true.

About My Hero Academia:

My Hero Academia or Boku no Hero Academia is the story of a quirkless boy Izuku Midoriya and how he backed the greatest hero alive. Midoriya, a boy who has been admiring heroes and their ventures since the day he was born, came into this world without a quirk. On one fateful day, he meets All Might the greatest hero of all time and discovers that he was quirkless as well. With his diligent attitude and unwavering spirit about being a hero, Midoriya manages to impress All Might and is chosen to be the heir to the power of One for All. Upon inheriting, he gets access to all the abilities of the No 1 hero.