Demon Slayer ran into a bit of controversy with its Entertainment District Arc and it's all thanks to a more visceral display of gore and other mature themes. Because despite the shonen tag, it doesn't shy away from graphic body horror and other forms of violence. Arguably, that's also what makes it a cut above the rest of shonen anime; it's not afraid to stay true to its source material.
Because in anime where measly humans go up against grotesque and overpowered demons, there are bound to be casualties. Suffice to say, Demon Slayer has some disturbing moments. While they're not as graphic as some of the more unapologetically dark anime like Attack on Titan, these scenes are either difficult to watch or are straight-up nightmare fuel.
8 Nezuko Turning Into A Demon (Season 1)
As if coming back home after toiling through a child labor job only to find that your family has been slaughtered doesn't seem unlucky enough, Tanjiro also has to go through getting assaulted by her very own sister. He probably least expected Nezuko to attack, but since she turned into a powerful demon, the show had to give the viewers a nasty image of Nezuko's transformation.
The shocking part was when she grew nearly thrice Tanjiro's size and went rabid. Things took a lighter and sadder turn when she suddenly cried and realized that she had been attacking her brother. During that moment, it's difficult to keep watching since the viewers who haven't read the manga were unsure whether Tanjiro would be forced to kill Nezuko or vice versa.
7 The Hand Demon (Season 1)
The Hand Demon is one of the first serious challenges for Tanjiro as it marked the end of his formal training under a former Hashira. The way the Hand Demon was introduced was quite traumatic as didn't reveal its true form initially and went for the element of surprise when attacking Tanjiro.
As the fight went on, it became clear that the Hand Demon was a hideous amalgam of arms that it collected from its hapless victims, who are also trainee Demon Slayers themselves. Granted, Demon Slayer has had some progressively creative and increasingly disturbing demon designs but the Hand Demon marked the first innovation.
6 Spider Demon Family Backstory (Season 1)
The Spider Demon or Rui is a member of the Twelve Kizuki, where she holds the position of the Lower Rank Five. That's plenty powerful enough for newbie Demon Slayers; Rui was even shown toying with the neophytes, where she made them all fight one another.
A deeper look into her past reveals something even more disturbing though; her Spider Demon Family is all made up and she adopted the cruelest and most dysfunctional members. The Spider Demon father physically abuses everyone else while Rui keeps them in check with psychological abuse. Not exactly an ideal arrangement even for a demon.
5 Muzan Punishes The Lower Moons (Season 1)
Near the end of the first season, viewers got a peek at how Muzan manages his lieutenants. It was organized, alright, but it was an ugly sight to behold. That's because Muzan turned out to be an atrocious and barbaric leader whose perfectionism doesn't leave room for mistakes or lack of ambition.
So he made an example out of the underperforming Lower Moon demons and horribly killed them on the spot. Despite being generally tough demons, their fear was palpable enough and resonates well with the viewers; the whole execution scene was unsettling and brutal.
4 Kyojuro Rengoku's Death (Season 2)
Kyojuro Rengoku's appearance was grand and energetic. It was the first time the anime finally set a power level for the Demon Slayer Corps. Kyojuro was supposedly near the top or around the middle of the Hashira ranking. That was why it was disheartening to see him get manhandled by the Upper Moon Three, Akaza.
To make his death more traumatic, Akaza effortlessly punched a hole through Kyojuro's torso like he was toying with a snowman. Then the dread sets in as the viewers realize that there's no recovery from that kind of wound and Kyojuro's done for. All that hope against Muzan's elite was crushed like a pile of dead leaves.
3 Tanjiro Beheading Himself (Season 2)
Also in Season 2 of the Mugen Train Arc, Tanjiro and the two other lower-ranked Demon Slayers had to tussle with Lower Moon One, Enmu. It was Tanjiro's toughest fight ever since progressing his strength after defeating Rui or Lower Moon Five. The results were commendable though rather unorthodox.
That's because Enmu's specialty is putting his victims in a trance where they dream of pleasant stuff. When Tanjiro fell under this spell, he had to wake himself up in the most unconventional and painful way possible: by decapitating himself in his dream. Theoretically, he could have just stabbed himself in the heart but slicing off his head was a more fool-proof tactic so viewers had to grit through that scene.
2 The Hashira Want To Kill Nezuko (Season 1)
It's amazing how Tanjiro and Nezuko managed to keep themselves alive thus far since there were moments in the anime where their plot armor keeps getting tested precariously. One time, Nezuko's plot armor nearly slipped off when she finally met all the Hashira of the Demon Slayer Corps.
All of them were adamant about their intent to execute Nezuko since that's part of their job and they're unrelenting professionals. It even looked like Nezuko was about to fail Sanemi's test to restrain herself from attacking at the sight of his blood. Thankfully, viewers were finally able to breathe after Tanjiro shouted some sense into Nezuko.
1 Gyutaro Comes Out Of Daki (Season 3)
By far the most recent unnerving scene in Demon Slayer happened during the Entertainment District Arc of Season 3. Just when the trio and Tengen Uzui thought that Daki was done for, out came Gyutaro emerging from her back like a spouting fungus. And he turned out to be an even more powerful member of the Twelve Kizuki, sharing the Upper Moon Six slot with his sister.
There's just something distressing about a fully grown demon man coming out of his sister's disfigured body. Even more disturbing is that he's actually a good brother to his sister, though it's also troubling that he chose to be inside his sister's body. That doesn't seem right......