The particular color of her hair would also be reminiscent of her family's history as Children of Fire, explaining the burnt red tinge at the ends of her hair. This implies that Nezuko's hair color represents the demon blood within her; as the color takes over her hair, she may succumb to her demon side more often.
Nezuko also wears a small pink ribbon on the left side of her head to keep her hair out of her face, along with the bamboo muzzle Giyu Tomioka gave her, which is secured around her jaw with a strip of red cloth.
Nezuko is known as a great beauty in her hometown according to Tanjiro. She appears as a fair skinned young girl, with long dark brown hair that reaches just below her waist, where it starts to take on a vermilion color at the elbows.
Nezuko, the young sister of the main protagonist Tanjiro, has a special Blood Demon Art called Exploding Blood that allows her to ignite her blood into pink flames and even summon it from thin air. Unlike other demons, Nezuko doesn't consume humans to grow stronger but instead rests to unlock her full potential.
Since Nezuko is from a Sun Breathing lineage, she can survive in daylight. After the final battle against Hantengu concludes, she can step into daylight, and many theories are available about the phenomenon. One of the theories is that her abstinence from consuming human blood is what saved her.
Nezuko having eaten the Blue Spider Lily at some point could explain her immunity to sunlight, and Demon Slayer: Kimetsu no Yaiba has already worked to justify that.
Secondly, Muzan would probably… eat Nezuko and Tanjiro in the hopes of obtaining their sun-resistance abilities, and also since he wouldn't be able to convince them to become demons to work under him. This would allow him to become the ultimate demon.
However, the trait that sets her apart from all other demons is the fact that she has the ability to conquer the sun, prompting the Demon King to call her the "chosen demon". Abnormal Demon Physiology: As the "chosen demon", Nezuko has several unique demonic traits that set her apart from all other demons.
Nezuko has several powers, including regeneration, superhuman strength, growing and shrinking rapidly and a blood demon technique called Exploding Blood (爆血, Bakketsu) that causes her blood to burn once it leaves her body.
Nezuko Has Suppressed Her Consciousness
Frequently, she is pictured carrying or soothing smaller siblings, clearly taking on a maternal role at a young age. However, after being transformed into a demon by Muzan Kibutsuji, the Demon King, she quickly regressed in mental age and maturity.
However, during the second season of Demon Slayer, she underwent a transformation and developed a horn, and her body resembled that of a grown adult. This seems to be her awakened mode and could be her true demonic form. There is no logical reason in relation to the plot that suggests why she has a horn.
At the start of the series, Nezuko's eyes were red and normal for a human. Once she was turned into a demon after her family's attack, her eyes changed into pink. Usually, we would think it's the other way around, but her pink eyes simply indicate her demonic nature.
Unlike other demons who survive on blood, Nezuko never really needs it, and she doesn't even consume human food either. Moreover, Nezuko has never shown any signs of undernourishment as she is always ready to assist her brother with her overwhelming strength and deadly Blood Demon Art.
Zenitsu crushing on Nezuko. Upon seeing her for the first time, Zenitsu falls in love with Nezuko at first sight. She apparently views Zenitsu as a "weird dandelion" and did not initially seem to reciprocate his feelings. Although the two are rarely seen interacting together, Zenitsu treats her with affection and care.
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.
Nezuko's Blood Demon Art is “Pyrokinesis,” which allows her to generate and manipulate special demonic flames created from her blood.
1 Exploding Blood/Pyrokinesis Blood Demon Art
By far, this is Nezuko's most damaging technique when it comes to fighting her own kind.
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.
So if Nezuko ate a human. and continued to do so over time, her power could rival that of Upper Moon one or 2, and here's why. One, if you're a manga reader, you know, in her base, Nezuko conquers the sun. And 2, her blood demon art can nullify.
Nezuko might be a terrifying demon, but she's also one of the cutest characters in anime.
Most importantly, Nezuko upholds a vow of silence by remaining mute throughout the series. The muzzle serves as a representation of Buddhist practices.
Due to her demon abilities, Nezuko can change her size/age and appear “mature” in a slightly older form or can even make herself look younger and smaller than a 12-year-old.
The two known demons who broke free of Muzan's curse are Tamayo and Nezuko. Tamayo was able to break free of the condemnation when Yoriichi fought Muzan, nearly killing him in the process.
With this in mind, if Nezuko had also been murdered by Muzan, Tanjiro would have no reason to be empathetic toward demons. Her transformation gave him a perspective of both demons and humans, but without Nezuko becoming a demon he would have no reason to take their feelings into account.
With her immense fondness for humanity, Nezuko broke out of Muzan's control, becoming free to do anything at her will. It is unclear if the curse branded to her by Muzan got lifted or not, but she can't speak a word after turning into a demon, and always has a muzzle in her mouth.