Abnormal Demon Physiology: As the "chosen demon", Nezuko has several unique demonic traits that set her apart from all other demons. Most notably, Nezuko can continuously restore her power without consuming any human blood like any other demon would need to do.
Her Blood Demon Art allows her to effectively control her own blood, such as in her fight against Daki (where she congeals her own blood to prevent herself from being sliced apart).
Nezuko's Blood Demon Art is “Pyrokinesis,” which allows her to generate and manipulate special demonic flames created from her blood. It may be because of her unique nature, but her flames have a special ability, making them only harmful to demons and anything related to demons.
Muzan can only not control two demons that are Nezuko and Tamayo. Nezuko is able to cling to all the humanity she has left and she can also block his influence on her. Her strong desire of protecting her brother and the devotion towards her family makes her hard to control for Muzan.
Well, there are many reasons for nezuko's cuteness. She shrinks, she lives in a box like a cat. She plays cute little games when she's bored. She loves giving and receiving pats on the head.
Nezuko might be a terrifying demon, but she's also one of the cutest characters in anime. There is absolutely no doubt about the fact that Nezuko is the star of the Demon Slayer anime.
Nezuko, Tamayo, Yushiro, and later Chachamaru are the only four demons not under the control of Muzan.
However, she wasn't immune to the sunlight initially, as she got burned badly at first. So, in conclusion, her coming from a Sun Breathing user's lineage and not relying on human substance are perhaps the reasons for her immunity.
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.
In episode 6 of Demon Slayer season 2, Nezuko entered a berserk state to protect her brother Tanjiro, causing her body to develop into that of an adult. She loses her gag, grows a single horn and gains vine-like patterns across her body.
While she might not be as powerful as Muzan himself, her overall strength makes her easily comparable to an Upper rank demon.
As the main threat occupying the position of Upper Moon Six, Gyutaro's Blood Demon Art is tremendously powerful and extremely dangerous. With it, he can perform various attacks using blood from different parts of his body, and project them from his sickles as well.
Pyrokinesis: Nezuko's Blood Demon Art allows her to generate and manipulate special demonic flames created from her blood that are pinkish in color.
1 Exploding Blood/Pyrokinesis Blood Demon Art
By far, this is Nezuko's most damaging technique when it comes to fighting her own kind.
The Wind Hashira is one of the strongest Hashiras in the Demon Slayer series. He played a significant role in defeating Kokushibo and was able to inflict damage on Muzan. Sanemi's sheer power and speed will be able to overwhelm Nezuko even in her final form.
The now-iconic bamboo muzzle serves as a way of stopping Nezuko from using her teeth, and also keeps her from tasting human blood, which would cause her to lose control of herself.
Since he didn't know anything about the Blue Spider Lily medicine, he needed others to find the plant for him by happenstance. This is the general reason why Muzan turned Nezuko into a demon. More specifically though, was the fact that Nezuko was of Kamado blood.
Nezuko's inability to speak is one of her character defining traits. However, one theory suggests a deeper meaning behind the silence. Nezuko is one of Demon Slayer's most popular characters, adored by fans for her cuteness. However, despite being so renowned, Nezuko rarely ever speaks.
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.
Speaking Muzan's name is considered a sign of disrespect and a challenge to his authority, and it is believed that doing so brings misfortune and suffering to the demon who utters it.
For those who have watched only the first season of the anime, they will be surprised to know that Muzan turns into a woman in the second season. He keeps transforming in order to hide his true identity, and he's even known to change into an 11-year-old child to hide from Demon slayers.
The young Tanjiro is not only one of the greatest demon slayers, but thanks to his kind nature, he's also one of the most honorable characters of the series. Tanjiro not only showed selflessness and love towards his sister and the people he cared for but even showed kindness towards his demonic enemies.
The most egregious example is Daki, though Nezuko also gets her moments of weirdly sexualized costume and plot choices. Daki is highly sexualized despite being biologically thirteen years old.
Since she's the Love Hashira, it just makes sense for Mitsuri to be one of Demon Slayer's kindest and most compassionate characters. She always compliments the people around her, even if it's just mentally. She can also find everybody's best qualities.