Deku’s on the other hand,uses neutral-polite Japanese,

but he would change his habit ENTIRELY during fights that he wished to win. Guess whose speech habit he imitates?

Japanese often don’t use subject in their sentence. But when they do there are level of politeness

First person (me):
1. Watakushi - super polite (gender neutral)
2. Watashi - polite (gender neutral)
3. Atashi - neutral (for female)
4. Boku - neutral ( for male)
5. Ore - least polite (for male)
There are others like “jibun”, “uchi”, “washi”, etc but lets not go there

Second person (you):
1. The most polite form is to mention their name and add honorific (-sama, -san)
2. Anata - polite (also means “darling”)
3. Kimi - neutral
4. Omae - impolite
5. Teme - rude

Deku uses [boku] as “me” and [kimi] as “you”. But during fights where he wants to win, he’ll switch to [omae]. In pic below he said “omae wo tomeru” (i will stop you)

In the raw panel he said “死ぃねぇぇぇ！！“ (shineeee) = “dieeee” which is kacchan’s trademark scream and very OOC considering deku’s original speech habit.

In the original panel he said “chikushou!!Tomare!! Kuso!”. [Dammit!! Stop (impolite form), shit!!] While normally he’d probably say “iya da, tomatte, onegai” [no, stop (more polite form), please]

In the original panel he said “uuurrrruuuuseeee!!” While his original way of speaking should be “urrrusaaaiiii!!” Both literally means noisy (commonly used to tell ppl to shut up), but the prior is less polite (kacchan’s habit)

In the original panel he said “konna mon ka yo”. In english it doesn’t sound as harsh, but in japanese he chose the most rude and shortest way to say “that all you got”. Something that kacchan would say, but not deku.

Aaaaand this is why:

In english it’s not as distinctive but in japanese it’s really clear when deku changed his way of speaking

Horikoshi gave every single character a VERY distinctive speech habit. But it’s not translatable to english.

In deku’s case it just sounded like he cusses like kacchan, while in Japanese it’s clear that he IMITATES kacchan’s way of speaking during fights

Btw of course kacchan uses “ore” and “omae/teme”