Yes probably. Nezuko is already very powerful, she was able to go toe to toe with Daki, this means she can probably become a uppermoon. But thank God that Muzan has no control on her and she's safe with
Nezuko is at least stronger than Daki, meaning that if Muzan could bring her back under his control, she would certainly qualify for the most prestigious title a demon can hold: a member of the Twelve Kizuki. Thanks to Nezuko's remarkable strength, she would have to be an Upper-Moon.
This willpower is also what helps Nezuko truly utilize her Awakened form, to fight more efficiently. While she might not be as powerful as Muzan himself, her overall strength makes her easily comparable to an Upper rank demon.
This means that there is a way for Nezuko to beat any of the Upper Moon 6 demons: Daki, Gyutaro, or Kaigaku. To do so, Nezuko would have to fight the demons outdoors and prolong the fight long enough for the powerful demons to be exposed to sunlight.
Nezuko can be ranked at the level of an Upper Moon 5 since she is considerably weaker than the likes of Kokushibo and Doma.
In conclusion, Nezuko cannot beat Akaza in Demon Slayer. In terms of power, physical abilities, regeneration rate and overall combat ability, Akaza is far superior compared to Nezuko.
Muzan, the King of Demons, is the strongest and also the primal demon in the world of Demon Slayer. Consuming his blood is enough to turn you into a powerful demon. He can control all the demons in existence, with only people with strong willpower like Nezuko being an exception.
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.
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.
Giyu is one of the legendary Hashira, and he's brought down demons far more powerful than Nezuko. With his level of skill and impressive agility, he'd easily defeat Tanjiro's little sister. In fact, when Giyu first meets Tanjiro and Nezuko, he almost does kill the latter.
Nezuko's Sunlight Immunity in Demon Slayer is Tied to the Blue Spider Lily. 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.
Nezuko's most significant trait, however, is her immense growth, which is likely due to a combination of the amount of blood she received from Muzan and her willpower. To conclude, Nezuko is a formidable powerhouse within the anime and is probably one of the strongest main characters in the series.
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.
Overall Abilities: As a Hashira of the Demon Slayer Corps, Nezuko is a very powerful and skilled swordswoman and combatant. Unlike her younger brothers, Nezuko had no superhuman characteristics, like extraordinary senses, a heightened sense of smell, or great intellect.
Her most prominent traits is her extraordinary growth rate possibly due to the high amount of blood she received from Muzan Kibutsuji when he turned Nezuko into a demon and the fact that she doesn't need to consume human blood to survive.
The divine nature of sun breathing: Tanjiro's link to Yoriichi. The flashback also reveals that Yoriichi had a twin brother named Michikatsu Tsugikuni, who became a Demon Slayer but later turned into a demon and became Upper Moon One, Kokushibo.
Nezuko, on the other hand, never was under Muzan's curse, it would seem. Instead, she used her will to protect her brother and other humans to fight off the curse. This is probably why Nezuko sleeps instead of eating humans. This also means her strength as a demon is based on her will to protect rather than feed.
This wasn't explained in the anime, but Nezuko was able to remove the curse of Muzan on her own way, just like what Tamayo (Demon doctor) did. This was when Tanjirou and co. arrived on the Butterfly estate after the Hashira meeting. As for how she removed the curse, it wasn't explained.
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.
If Nezuko were to taste blood, it's likely that she would lose control completely, forcing Tanjiro and other demon slayers to kill her. So the bamboo gag really protects Nezuko as well as the other humans the slayers may encounter on their journey.
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.
Sanemi's sheer power and speed will be able to overwhelm Nezuko even in her final form. Nezuko's Blood Demon Art would not work against Sanemi since he's a human, and he has the ability to decapitate her head if he wanted to.
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.
3 Nezuko Is The Friendliest Demon In The Series
But as a demon, she's proven her loyalty to not only Tanjiro, but to humanity as a whole. Unlike most demons, Nezuko managed to retain most of her human emotions.