From the beginning of the series, Kibutsuji Muzan was established as the most fearsome demon in existence. He is responsible for the creation of all other demons in the series, of which most are still extremely fearful of him, as he has been shown to slaughter subordinates that displease him.
1 Kibutsuji Muzan
In the anime, little is known about Kibutsij Muzan and his powers, other than he is the Demon King and creator of all demons. He is both respected and feared by his underlings and is the sworn enemy of the Demon Slayer Corps. Muzan's only weakness is his aversion to the sun.
Yoriichi Tsugikuni is the strongest demon slayer ever, as he was born with the demon slayer marks. He single-handedly invented the original sun-breathing style.
How Doma became the worst demon in Demon Slayer. Almost every creature possesses emotions, be it anguish, sorrow, happiness, or even fear. However, in the case of Doma, he doesn't feel a thing. During his childhood, his mother stabbed his father to death for cheating on her and, later on, took her own life.
Doma is one of the most ruthless and insanely strong demons under Muzan Kibutsuji. As Upper Moon 2, he proves to be the absolute antithesis of Akaza. Moreover, their contrasting personalities as demons or mannerisms of rising up in the ranks are the major reasons for Akaza's hatred towards Doma.
Her background as a courtesan coupled with her beauty meant that she would serve as a great and reliable source of income for Muzan, which is why the Demon King decided to be tolerant of her apparent stupidity.
Shinobu Kocho is a capable Demon Slayer whose worthy of being the Insect Hashira. That being said, she's arguably the weakest Hashira when it comes to pure strength.
The warrior Muzan feared was a swordsman named Yoriichi Tsugikuni. Yoriichi was the only slayer before Tanjiro who came close to killing Muzan, and the flashback of their fight occurred in Chapter 187.
Tanjiro decapitates Akaza with the Hinokami Kagura: Setting Sun Transformation. Akaza was bewildered, wondering how Tanjiro did not have any fighting spirit, comparing this feeling to fighting against a plant. He acknowledges that Tanjiro surpassed his speed.
He was soon decapitated by the combined force of Kanao and Inosuke, avenging Shinobu and her family. Trying to struggle for survival like Akaza, but lacking indomitable willpower as Akaza had, Doma's head slowly disintegrated and he met Shinobu's soul in the limbo, holding his severed head.
The Mist Hashira, along with Gyomei, Sanemi, and Genya, fought the Upper Moon 1. While the group was able to defeat them, both Muichiro and Genya died due to the wounds inflicted by Kokushibo.
Anne was a kind and loving soul and was described as the only person that Muzan had truly loved, besides his three daughters.
Does Muzan have a favorite demon? Despite the fact that Muzan. is always shown to have disdain for his creations, Muzan does in fact have a favorite. On that list is Naki, made due to a convenient blood demon.
Muzan is very cunning and intelligent. He is perceptive enough to be able to seamlessly blend into human society and he even started a family. He can hide his evil side and put on a friendly facade if necessary. He is manipulative and can quickly get people on his side for him to use them.
Going beyond this, Giyu is one of the most combat-proficient Demon Slayers seen throughout the entire series. Furthermore, his strength and abilities are always portrayed as seemingly a cut above the rest of the Hashira, solidifying his expected victory against Tanjiro.
Gyomei used his weapon to hold him back while Sanemi, Giyu, and Tanjiro used their Breathing techniques to attack him. With the collective efforts of every member of the Demon Slayer Corps present there, Muzan turned to dust as sunlight came in contact with his body.
Does Tanjiro have the skills to become a Hashira? Although Tanjiro remains at the fourth bottom of the hierarchy in the Demon Slayer Corps, he has always been strong enough to become a Hashira. Just the fact that Tanjiro has a fully developed permanent Demon Slayer Mark is a testament to his skills.
But there is one who is the friendliest of them all, and that is Kiyogiro Rangoku, the Flame Hashira. Among the pillars, there is not a single negative thing revolving Rangoku. Such an honest guy, and his character influences others positively. In Demon Slayer, Liu and Rangoku are not shown to have any interactions.
Tengen Uzui
He is the fastest Hashira, and the second physically strongest. Obviously, then, Tengen Uzui is rather proud. He is demanding, fussy, boastful, and prone to selfishness. But he is also ultimately kind and caring, with great love for his three wives as well as the other Hashira.
The Wind Hashira has one of the saddest backstories in Demon Slayer. His mother had turned into a demon and had killed five of his siblings. He was forced to kill his own mother in an attempt to save his only remaining brother, Genya.
It is revealed that Muzan's true fear of dying and immense desire to live and survive was due to him being born "dead," where his heart would constantly stop in his mother's womb and was assumed stillborn until he fought to breathe before his cremation.
Curse of Kibutsuji
The curse prevents Muzan's name from being spoken aloud, and any who do will meet a horrible demise. One demon, Susamaru, faced this reality when battling Tamayo. Susamaru accidentally shot Muzan's name aloud, attempting to defend his honor with her mind clouded.
The only two people she really cares for are Muzan Kibutsuji and her older brother. She shows deep respect for Muzan Kibutsuji immediately falling into a bow when he appears. Although she cares and loves her brother she is seen insulting and blaming him at times when things aren't going well.
Akaza is an upper-rank-three Demon and one of the most faithful minions of the Demon king Muzan Kibutsuji.