#they have an interesting parallel okay - in a series full of mentor/mentee and successor relationships

[delawaredetroit]

So after Sir Nighteye's verdict that he couldn't approve of Izuku as the One for All successor, Izuku takes that as an insult to everything that he is. In other words, Izuku at this point in the manga recognized himself as a person through the roles of All Might's disciple and as the One for All successor.

There's a reason the Overhaul Arc is Izuku's most Touya kinnie arc. Young Touya believed the reason for his existence was to be his father's successor who would fulfill Endeavor's dream of defeating All Might. Touya viewed himself as a person through that lens. Then he slowly lost it after this role was given to someone else.

Izuku seemed rather emotionally unstable in the Overhaul Arc for a similar reason. Someone was trying to take away the role that he believed defined him as a person.

It's more speculative on my part, but if All Might had shown more interest in Mirio other than the dismissive attitude he had in canon, Izuku might have had some mini young Touya adjacent meltdowns...