The two main star characters of Demon Slayer are the titular faction itself and their eternal enemies, the demons. It's more than a classic case of good versus evil and sometimes borders on modernity versus tradition as it's set during the start of the industrial age. Regardless, the Demon Slayer Corps always have their hands full with all the roaming demons around.

RELATED: Demon Slayer: Every Major Character's Age, Height, And Birthday

While the anime hasn't brought out its biggest guns yet, some of the demons are outright evil and spine-chillingly remorseless that it's easy to see how much of a menace they are to humanity's progressing civilization. In the anime's first season as well as the Mugen Train arc (film + anime), these evil Demon Slayer characters are sure to make Tanjiro and Nezuko's journey too difficult.

Updated May 29, 2023 by Ritwik Mitra: Demon Slayer is a series that has taken over the world by storm, with the Swordsmith Village arc proving to be just as riveting as everything else the series has shown to date. The show is filled with many unique characters who are instantly recognizable courtesy of their distinctive character design and unique personalities, with the vast majority of the show's characters being quite pleasant and engaging.

However, not all characters in Demon Slayer are joyful in such a manner. The world of this series is a dark and foreboding one where demons lie in wait at every corner for fresh meat, with the strongest of the bunch almost treating the act of killing humans like a sport as opposed to something they need to do. Some of the humans in the show are also shown to be quite evil in their own right, although this is mostly to do with the world they live in as opposed to them being inherently bad to the bone.

18 Hantengu

Hantengu from Demon Slayer
  • First appearance: Season 3, Episode 1
  • Rank: Upper Rank Four

It's only a given that the members of the Twelve Demon Moons are bound to be quite evil in their own right, and Hantengu is no exception to this golden rule. Fans who have been following Swordsmith Village know precisely how evil this character is, with his power being truly astounding in every way.

Before he was a demon, Hantengu was a thief and killer who always tried to deflect any blame from himself by convincing people that he was twisted in the head. While this was the truth, this in no way excused the fact that Hantengu is a psychotic killer who reveled in the act of destroying lives and eating humans to become as strong as possible.

17 Kokushibo

Kokushibo in Demon Slayer
  • First appearance: Season 3, Episode 1
  • Rank: Upper Rank One

Kokushibo is one of the most unique demons in the show, being the demon who holds the highest rank in the Upper Demon Moons. He's a force to be reckoned with, and fans can't wait to see this demon in his glory when the anime finally gets around to the arc that covers his battle. The fact that he's the brother of the man who invented Sun Breathing makes him a great personality who is bound to expand the lore and history of the show in new and exciting ways.

However, there's no denying that Kokushibo is a horrible entity that feeds off the misery of human beings. His jealousy of Yoriichi led him down a dark path where his insecurities got the better of him. This led to him trading his humanity to become a demon who would use his power for evil...even though he still couldn't hold a candle to his brother's ability even after taking all these measures.

16 Gyokko

gyokko-evil
  • First appearance: Season 3, Episode 1
  • Rank: Upper Rank 5

There's something especially evil about a demon who revels in the act of eating children, and Gyokko has shown these disturbing tendencies from an early age. After his parents drowned at sea, Gyokko found their corpses and developed an unhealthy obsession with these cadavers, leading to him killing a child and stuffing his body in a jar for his morbid amusement.

RELATED: Demon Slayer: Characters With The Saddest Backstories

While the villagers who ostracized him are also to blame for his downfall, Gyokko certainly didn't do himself any favors by preferring the meat of children after he was turned into a demon by Muzan. The manner in which he stuffed his victims into pots to turn them into his grotesque definition of art is evil and makes him one of the most heinous characters in Demon Slayer by a country mile.

15 Obanai Iguro

Obanai Iguro, The Serpent Hashira in Demon Slayer
  • First appearance: Season 1, Episode 22
  • Rank: Hashira

Well that's an odd one, isn't it? Obanai is a Demon Slayer, not a demon. But, those who have read the manga will know that he might as well be a demon thanks to his personality and general attitude toward the Demon Slayer Corps. He's highly critical of the other Hashira or officials and even forced a heavily injured comrade to stay in the Corps just because.

Moreover, Obanai regards the lower-ranked Demon Slayers are useless, expendable fodder and will likely not hesitate to use them as bait or sacrifice to achieve a victory. One of the few reasons he remains in the corps is that he's one of the most powerful Hashira and is a one-man army himself. It's also worth noting that Obanai's family is an evil clan who worship snake demons and some of their moral compass might have rubbed off on him.

14 Doma

Demon Slayer - Doma Smiling Down At Gyutaro In A Flashback
  • First appearance: Entertainment District Arc, Episode 11
  • Rank: Upper Rank Two

Doma is a chilling Upper Rank demon who looks quite menacing indeed. His appearance was merely a flashback, and he was just Upper Rank Six at that point but even then, he was already unapologetically malicious.

He's seen feasting on the corpses of slain courtesans like they were snacks he brought along the way. It's also worth noting that even his other Upper Rank comrades dislike him. Akaza, for example, finds Doma's indiscriminate killing of humans distasteful since the former prefers to kill and eat combatants.

13 Gyutaro

Gyutaro anime demon slayer
  • First appearance: Entertainment District Arc, Episode 7
  • Rank: Upper Rank Six

Gyutaro was a part of Muzan's Twelve Kizuki and was the joint-holder of the Upper Rank Six position along with his sister, even though the Demon King believed that Gyutaro had more potential than this. The tragic part about Gyutaro's evil ways is that he was forced to become like this thanks to his brutal upbringing.

RELATED: Demon Slayer: Best Moments In The Anime's Entertainment District Arc

Gyutaro doesn't care about anyone else but his sister and would happily harm or torture anyone else. While he isn't exactly the evilest out of all the high-ranking demons, his disregard for mortal life paired with his skills makes him highly dangerous, even as a corpse.

12 Daki

Daki the demon in Demon Slayer
  • First appearance: Entertainment District Arc, Episode 3
  • Rank: Upper Rank Six

One can even consider Daki as the more evil between her and Gyutaro since she didn't have as many excuses as her brother. She was raised to be selfish and to only care for herself like a spoiled brat. As a result, she notably caused more trouble for humans than Gyutaro did.

Daki ran the Entertainment District with fear, killing any courtesan or civilian out of her whim or due to a mere tantrum. She even treats her brother badly and doesn't mind calling him ugly or disowning him despite being too dependent on him.

11 Swamp Demon

Swamp_Demon in demon slayer
  • First appearance: Season 1, Episode 6
  • Rank: None

There was bound to be a demon who uses his power to traumatize victims and become a menace to society because humans can't stop him anymore. The Swamp Demon was one such individual and he's one of the most wicked demons in the series since he prefers his victims to be girls or young women.

To that end, he's like the local Jack the Ripper in this Meiji-era Japan except more disgusting since he also chooses younger targets, specifically 16 years old and below. While other demons had some tragic backstories that sort of justified their crimes, the Swamp Demon is merely despicable.

10 Yahaba

yahaba in demon slayer
  • First appearance: Season 1, Episode 8
  • Rank: None

Yahaba isn't unlike Gyutaro since he also has a female partner in crime who isn't unlike Daki. Among the two aspiring demons though, Yahaba is more level-headed and more mature. He prefers to execute his victims more cleanly and always plans out their demise.

RELATED: Demon Slayer: All Water Breathing Techniques, Explained

That's what makes Yahaba more sinister. Whereas his partner, Susamaru, goes by instinct and impulse, Yahaba plans out how to cause the most harm to his enemies. He also has quite an ego as even in death, he despises Tanjiro for "humiliating" him.

9 Susamaru

susamaru in demon slayer
  • First Appearance: Season 1, Episode 8
  • Rank: None

Some viewers might have forgotten about Susamaru already as she had a brief stint before perishing to Tanjiro's group. However, she's popularly known as the Temari Demon who used balls to kill her victims and even toy with them as if killing them was a game.

That makes Susamaru one of the more detestable demons in Demon Slayer. Killing is a sport for her and torturing her victims is merely a game she plays. It's a good thing Tanjiro cut her tenure short as she would have made for one of the most maniacal high-ranking demons if she made it to the Twelve Kizuki.

8 Rui

Rui in Demon Slayer
  • First Appearance: Season 1, Episode 15
  • Rank: Lower Rank Five

Speaking of the Twelve Kizuki, Rui is one of the featured members of Muzan's elite corps and she's quite a troubled demon herself. Rui grew up aspiring for nothing but a family of her own where she's loved and cared for. Sadly, demons took advantage of this and turned her into an evil creature with a twisted version of a demonic family.

Rui is thus one of the most powerful members of the spider demon family and constantly abuses her younger siblings. One can understand why Rui does this as she had no experience with a loving family, however, that doesn't justify her toxicity and evil tantrums.

7 Father Spider Demon

Father_Spider_Demon_looking_for_Inosuke in demon slayer
  • First Appearance: Season 1, Episode 16
  • Rank: None

While it might seem like the Father Spider Demon is the most powerful among the Spider Demon family, that character is actually Rui. Father Spider Demon is, nonetheless, the most imposing among them thanks to his size and malformed appearance.

RELATED: Demon Slayer: All Sun Breathing Techniques, Explained

His powers are thus more physical in nature, to the point that he tends to abuse the other Spider Demon family members, such as his wife or Rui's siblings. At times, he also just abruptly slashes and hurts his family members out of anger or disappointment.

6 Kyogai

drum demon in demon slayer

  • First Appearance: Season 1, Episode 11
  • Rank: Former Lower Rank Six

Kyogai is almost as pathetic as he is evil. He was one of the Twelve Kizuki, Lower Rank Six to be precise, but he was kicked out of the elite corps after failing to maintain his power. He simply grew too complacent and lazy after killing so many humans just to attain his rank.

All those deaths for nothing, simply because Kyogai wanted to be left alone to play his drum in his dank lair. It's not only selfishly evil but also insulting to all his victims who had to endure being drummed to death by this silly monster.

5 Hand Demon

Hand_Demon_about_to_kill_Sabito in demon slayer
  • First Appearance: Season 1, Episode 4
  • Rank: None

The Hand Demon is one of the most grotesque and otherworldly out of all the demons in Demon Slayer. His appearance is barely humanoid as a result of all the victims he killed and/or devoured. That alone makes him an imposing immoral figure in the show.

To make matters worse, the Hand Demon only preys on the weaker Demon Slayers, specifically the trainees who are mostly fresh out of their teenage years. This predatory behavior probably doesn't earn him too much respect among his peers. The fact that he got killed by a trainee also doesn't help this evil cowardly demon's case.

4 Nakime

Nakime in Demon Slayer

  • First Appearance: Season 1, Episode 26
  • Rank: Upper Rank Four

Nakime doesn't exactly talk nor do much in the course of Demon Slayer's run. Her appearance is also too brief to calculate the extent of the damage she can do to any Demon Slayer's psyche. Still, based on her rank and powers alone, she'll give Tanjiro and even the Hashira plenty of trouble in the future.

RELATED: Demon Slayer: The Best Breathing Techniques & Who Can Use Them

It seems Muzan handpicked Nakime to round up the weakest links in the Lower Rank demons so that he can torture and kill them much easier. Nakime's power of creating an infinite castle to trap and confuse her prey, like a spider toying with a webbed insect, is one of the most terrifying abilities in the Twelve Kizuki. The fact that she also stood by and watched as Muzan's Lower Rank demons were tormented is also pretty chilling.

3 Akaza

Akaza in Demon Slayer
  • First Appearance: Mugen Train Arc
  • Rank: Upper Rank Three

While on the topic of Upper Rank demons, Akaza got a debut in the Mugen Train movie and made a pretty strong impression. Needless to say, he entered the stage with quite a bang and even managed to kill one of the Hashira, Kyojuro Rengoku.

When compared to the Lower Rank demons or even the rankless demons, he seemed rather fair. It's just that Akaza cares for little other than getting stronger and is a sadist who loves to see his enemies get hurt.

2 Enmu

Enmu in Demon Slayer

  • First Appearance: Season 1, Episode 26
  • Rank: Lower Rank One

Enmu was one of the fortunate Lower Rank demons who survived Muzan's disappointment in the first season, and he went on to become a literal horror train with a Freddy Krueger twist. As with all Lower Rank or weaker demons, Enmu preyed only on the weak.

Enmu lured desperate or dying individuals and turned them into his servants with the promise of letting them live out their best lives in their dreams. He's essentially offering them an equivalent to narcotics and further deteriorating their morals and psyche.

1 Muzan

Muzan Kibutsuji in Demon Slayer
  • First Appearance: Season 1, Episode 6
  • Rank: Demon King

No one expected the Demon King to look like Michael Jackson in his "Smooth Criminal" music video but that only made Muzan even more enigmatic. He's no doubt evil despite the mysterious motives and methods though. He has no qualms about ruining mortal lives just because he can.

It does seem that Muzan's ultimate goal is always dominion over the world of mortals or to turn everyone into a demon. He's not just cruel to humans but also to his demon minions as he constantly tortures, belittles, and makes them compete with one another. That goes to show what someone can do if they're allowed to do anything they want.

MORE: The Best Things About Demon Slayer: Kimetsu No Yaiba – The Hinokami Chronicles (& The Worst)