15 Obanai Iguro
- 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 about 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 in order 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
- First appearance: Entertainment District Arc, Episode 11
- Rank: Upper Rank Two
Doma or Douma is the latest Upper Rank demon to be introduced in the anime (at the time of writing) and he’s looking menacing as ever. 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
- First appearance: Entertainment District Arc, Episode 7
- Rank: Upper Rank Six
Gyutaro is the latest casualty in Muzan’s Twelve Kizuki and while he’s Upper Rank Six, the demon king believes in Gyutaro’s impressive potential. The tragic part about Gyutaro’s evil ways is that he was forced to become like this thanks to his brutal upbringing.
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
- 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
- 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
- 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.
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
- 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
- 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
- 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.
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 Drum Demon
- First Appearance: Season 1, Episode 11
- Rank: Former Lower Rank Six
Drum Demon 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 the Drum Demon wanted to be left alone to play his drum in his dank lair. It’s not only selfishly evil but also insulting for all his victims who had to endure being drummed to death by this silly monster.
5 Hand Demon
- 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 Slayerââââââ. 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
- 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 first season. 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.
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. That and she also stood by and watched as Muzan’s Lower Rank demons were tormented.
3 Akaza
- First Appearance: Mugen Train Arc
- Rank: Upper Rank Three
While on the topic of Upper Rank demons, Akaza recently got a debut thanks to the Mugen Train movie and that arc’s anime series version. Needless to say, he entered the stage with quite a bang and even managed to kill one of the Hashira, Kyojuro Rengoku.
Actually, 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
- 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
- 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.
