Summary

  • Previous wielders of One For All discovered the quirk shortens lifespan when someone has multiple quirks.
  • Deku learns about the burden of using One For All.
  • This revelation raises questions about Deku's lifespan despite being quirkless.

In Season 6 of My Hero Academia we learn more about the costs and consequences of the One For All quirk as it has passed through its multiple wielders. After an intense battle, Deku is hospitalized and unconscious. It is during this time that the vestiges of the previous wielders take the opportunity to speak with Deku to discuss what they have discovered about their shared quirk, which has implications for a wielder's lifespan.

As it is explained in episode 131 of My Hero Academia, a vessel that is not qualified to receive the increasing power of One For All will eventually break down prematurely, causing the user to have a shorter natural lifespan. How does this revelation affect Deku, and if he continues to persist after defeating Toma Shiguraki and All for One, will his lifespan be shortened as well?

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An Unsettling Discovery

Deku Meets With the Previous Wielders

deku One For All
Deku converses with the previous wielders of One For All inside his head.

Thanks to the connection that Toshinori Yagi aka All Might has to both the vestige realm and the real world, the previous wielders of One For All are able to investigate their common quirk more thoroughly, even after death.

Deku is summoned to a meeting with them, where they reveal how the fourth wielder, who previously assumed he died from an illness or failure to train, actually died from natural causes at the young age of 40.

“The ‘natural causes’ that killed me were due to the multiple quirks inside my body. They drastically shortened my lifespan.” -Hikage Shimori, fourth wielder of One For All.

This shocking revelation added stakes and exposed an additional burden associated with One For All. Because the power had grown so strong by being passed on so many times, it had grown past the point that regular people were capable of using it.

“We discovered I died at old age…What this fact leads us to believe is that One For All can’t be safely wielded by an ordinary human being.” -Hikage Shimori, fourth wielder of One For All.

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What This Means for the Future

How Does This Affect Deku?

deku full cowl
Deku runs while empowered by One For All. (My Hero Academia)

This new information had dramatic implications for Deku as the current wielder. It was only because both All Might and Deku had been quirkless recipients of All For One that these implications were even able to be figured out.

“By some twist of fate, this ability that’s passed from person to person, could only reach its true potential when wielded by someone born powerless.” -Yoichi Shigaraki, first wielder of One For All.

One For All had grown so powerful that it could no longer be passed on easily. This meant Deku might either be stuck as the last wielder of the power, or he would have to get lucky and find one of the increasingly rare quirkless people left in the world.

“Ya get what this means kid? You might be the last person who wields One For All.” -Daigoro Banjo, fifth wielder of One For All.

But what does this mean for Deku’s own lifespan in My Hero Academia? Despite being quirkless himself, we see how Deku’s body has been breaking down as he continues to use One For All. Does this mean Deku will have a shorter lifespan also?

To answer this question, we must look at All Might, who managed to use One For All for 40 years without any seeming lifespan issues. When Yoichi described All Might’s turn with One For All, he said his vessel was perfectly fit to handle its power at the time. This was why All Might could use the quirk at 100% right away, and only needed to be trained in combat skills by Gran Torino.

Contrast this with Deku, whose body had to be extensively trained to even be able to accept the quirk. Then, as he tried to use it, his body would instantly break down. This suggests that either Deku’s body is too weak to handle the power, or that One For All has grown so strong that there may not be another human vessel whose body could handle the transfer again without negative effects.

What this ultimately means for Deku’s lifespan remains to be seen. While he won’t suffer some of the ill effects of the power because he was born quirkless, it’s still likely that abusing the power the way he did will have some effect on his lifespan. If the series ever skips ahead a few decades to where All Might dies naturally or Deku is shown aging, we may get a definitive answer over whether One For All decreases a person’s natural lifespan, regardless if the wielder is quirkless.

My Hero Academia can be streamed on Crunchyroll.

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Release Date
2016 - 2025-00-00
Network
TBS, MBS, Nippon TV
Directors
Shouji Ikeno, Tsuyoshi Tobita, Ikuro Sato, Takudai Kakuchi, Masashi Abe, Tetsuya Miyanishi, Kazuma Komatsu, Yoshifumi Sasahara, Masayuki Otsuki, Daisuke Tsukushi, Takayuki Yamamoto, Yohei Fukui, Takuro Tsukada, Masatoyo Takada, Naomi Nakayama, Sayaka Morikawa, Takanori Yano
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  • Cast Placeholder Image
    Daiki Yamashita
    Izuku Midoriya (voice)
  • Cast Placeholder Image
    Kaito Ishikawa
    Manga Fukidashi (voice)

WHERE TO WATCH

Streaming
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In My Hero Academia, some humans have superpowers called quirks. Izuku Midoriya, nicknamed Deku, is not one of them. Deku has always idolized heroes like the number one hero, All Might, and since he was a child, he has always wanted to be a hero. However, his lack of a quirk has always held him back, but a chance encounter with All Might after discovering a classmate in danger sets Deku on the path to becoming a true hero. My Hero Academia centers around Deku and a class of heroes-in-training at UA. This school shapes young quirk users into future heroes through fake rescue missions, combat training, and other hero-tempering tasks. With young Deku inheriting the "One-For-All" quirk, he will learn what it means to be a true hero while facing off with dastardly supervillains.