The only reason why Muzan hates Doma is because of his insincerity and lack of emotions. This might sound odd, expecting emotions from a demon, but even a demon has to retain such tendencies to keep things in order.
Because of his desire to become stronger and Doma's strength allowing him to surpass himself to become Upper Two, Akaza harboured an intense hatred of Doma.
Yet an official Demon Slayer "fanbook," written by the manga's creator, Koyoharu Gotouge, revealed Muzan doesn't really like Upper Rank Two demon, Doma. As Lower Ranks Six, Four, Three and Two can attest, Muzan is not averse to eliminating demons he doesn't care for, even if they're Kizuki.
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.
Apparently, in Demon Slayer, Doma is the most awful demon in the series, towards whom even Muzan shares a strong hostility. So without any further ado let's dive right into why Doma is labeled as the worst of all demons.
The only Demon he despises the most is the Upper Rank Two: Doma. It is quite a shocker that the second most potent Demon in the Demon Slayer is not Muzan's favorite.
3 Muzan Mainly Liked Daki Because Of Her Potential To Earn Money.
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.
Tanjiro Kamado
Tanjiro is considered to be Muzan's main nemesis throughout the series.
1 Muzan Regretted Killing His Doctor
He shows his most human side to fans, wherein he admits to regretting murdering his doctor. He comments that had he been patient, the doctor would have cured him, and he would never have turned into a demon.
History. Doma was born with beautiful and rare rainbow colored eyes. Because of this unusual trait, his parents thought that he was able to hear the voices of God and was groomed to be the religious leader of the Eternal Paradise Cult, a position that he held until his death.
Trivia. Anne was originally planned to be Muzan`s older sister, who died by the hand of a Demon Slayer but that idea was scrapped, as the author knew practically nothing about Muzan`s early life. Instead, Anne became his wife, by which he had two children.
After Akaza's death, Doma says that he felt as if the Upper Rank had turned into a different creature before he died, and that his demise is inevitable because he never ate any women. Doma begins to cry over his 'best friend's' death, but Kanao just tells him to stop with the lies.
Despite being a blood-thristy demon who has murdered several people, he has a set of principles he adheres to. One thing that Demon Slayer fans have noticed is that Akaza refuses to eat or kill women. Additionally, the Demon King, Muzan, gave Akaza special permission to do so.
His hatred of weak people and belief of Social Darwinism stems from a corruption of his human memories, where a rival dojo poisoned his dojo's well because they were never able to beat him.
The only thing he's weak to is the sun. That is why he turned other humans into demons and spread his blood so that one of them might find a solution against the sunlight, so he can become truly perfect.
The explosion, which was enhanced by spike traps, manages to injure Muzan. Before he is able to regenerate fully, Tamayo appears and uses her Blood Demon Art to keep him in place, while using a drug that can turn him into human. Using this opportunity, Gyomei Himejima appears and destroys Muzan's head.
Yoriichi Tsugikuni was the first Demon Slayer and also the one who invented Breathing Techniques in the first place. Yoriichi was born with the Demon Slayer mark and prowess in swordsmanship. His powers were beyond comparison as he defeated Muzan once and had him on the verge of death until he managed to escape.
Tanjiro's ancestor was a good friend of Yoriichi and arguably was one of his only true friends. Therefore Yoriichi gave the earrings as a gift, and since then they have been passed down the generations until they reached Tanjiro.
Post-Transformation
Sensing their despair, Doma offered a chance to him and turned both Gyutaro and Daki into demons.
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.
Daki is highly sexualized despite being biologically thirteen years old. While it could be argued that her sexualization is part of her story, as she is a courtesan, it still can leave more mature fans feeling a little weird.
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.
3 He Manipulated Rui When He Was At His Weakest
It was only later he realized they did love him, and that he was the one who was never able to recognize their love. However, Muzan showed up at that very moment and brainwashed young Rui.