Even though My Hero Academia has charming characters and mostly motivational and heartfelt stories, the creators never shied away from exploring darker themes. Some of the most memorable My Hero Academia episodes are deeply emotional and shockingly dark and even dealt with adult themes, including mental illness, torture, and familial violence, while also always offering powerful life lessons.

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MHA fans could enjoy some of anime's most action-packed horror stories while watching intense battles unfold as new terrifying villains and quirks got introduced. Viewers could explore spooky stories and deep dive into many characters' heartbreaking backstories while meeting some of the most powerful and infamous anime characters with split personalities and deadly powers who use their unique abilities to make heroes and the public leave in fear and pain at all times.

7 The Truth About Nomu

Nomu in My Hero Academia

The episode in which the League of Villains attacked the Class 1-A students at the U.S.J. was one of the darkest My Hero Academia episodes for many reasons. It was the first time the promising students got a real taste of things to come when they become pro heroes and the kind of monstrous villains they'll have to face on a daily basis.

While all of the villains were terrifyingly strong on their own, it was also the first time that viewers and U.A. High School students saw a Nomu in action. Soon it became clear that Nomu are the strongest artificial humans in MHA who were being made from the corpses of humans.

6 Todoroki's Horrible Childhood

Todoroki in My Hero Academia

Todoroki is one of the most powerful anime characters with heartbreaking backstories, and in the episode in which Bokugo and Todoroki finally face each other in season two of My Hero Academia, fans could also learn more about Todoroki's childhood and why he's not using his fire-related quirk powers.

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While Endeavor was an intimidating character from the start, he became a truly mortifying one in most viewers' eyes once they found out that he tortured his own children, so he could turn them into the number one hero one day. He was the harshest on Todoroki and caused many physical and mental injuries during the unnaturally harsh training.

5 The Dark Secret Behind One For All Quirk

All For One in My Hero Academia

Over the years, fans could see some truly mighty heroes and terrifying villains and get to know some of the scariest powers in My Hero Academia. However, no quirk was as powerful as One For All. Many brave heroes possessed this transferrable quirk who all fearlessly fought some of the deadliest villains.

However, it was shocking for My Hero Academia fans to learn that One For All was actually created by All For One. He would force various quirks on his younger brother Yoichi who became the first hero who tried to defeat his much stronger older brother since he didn't want to be used as a pawn in his evil plans.

4 Mirio Loses His Quirk

Mirio in My Hero Academia

Mirio Togata, aka Lemillion, quickly became a fan-favorite character thanks to his friendly personality and tenaciousness. While he seemed like a character who is always smiling and has no problems, My Hero Academia fans soon found out just how much mental and physical pain he had to endure to learn how to use his quirk.

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Mirio bravely fought against villains while he was trying to protect Eri and showed MHA fans that he not only learned how to use his quirk well but is a truly honorable young hero. Seeing him lose his quirk after all the hard work he put in was one of the darkest and most heartbreaking moments in the series.

3 Dark Deku

Deku in My Hero Academia

Even before season six of My Hero Academia, fans could see some of the most impressive and strongest powers of Izuku Midoriya, but the evil version of Izuku Midoriya, Dark Deku, aka Black Deku, is truly a force to be reckoned with. Deku's transformation into something evil shocked his friends as well as MHA viewers.

Seeing this always positive and motivational character lose hope and that special spark was one of the darkest moments in the series. However, thanks to Deku's transformation, MHA fans could see some of the most thrilling and brutal fight scenes so far.

2 Shigaraki Murdered His Family

Shigaraki in My Hero Academia

Tomura Shigaraki is one of the scariest but smartest villains in My Hero Academia who, thanks to his unique design and fascinating quirk, quickly became a fan-favorite character. Thanks to a highly emotional episode in season five, fans could finally learn more about this intriguing villain's backstory.

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During the episode, fans could see Tomura as a child and learn about his family and how his father's brutality and hatred towards heroes as well as his family's ignorance, eventually led to Tomura's mental breakdown. After Tomura was betrayed by his sister, the last family member who was always there for him, his quirk suddenly activated, and he ended up accidentally murdering his entire family. By the end, Tomura discovered just how much he enjoys using his quirk and destroying things.

1 Overhaul Tortured A Child

Overhaul and Eri in My Hero Academia

While there are plenty of scary villains in My Hero Academia, none are as despicable as Overhaul. Kai Chisaki, aka Overhaul, did plenty of terrifying things and would even murder heroes as well as villains who stood in his way.

However, keeping a young child locked up and torturing her to learn how to use her powers for his own gain was the worst thing Overhaul ever did. Because of the horrible mental and physical torture Eri had to endure, she became one of the youngest anime characters to hate their powers.

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