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2025 is going to be an exciting year forDemon Slayerfans, because the anime is going to reach its epic conclusion. Rather than having a final season like most anime, though,Demon Slayeris going to have a trilogy of movies that bring the final Infinity Castle arc from the pages of manga to the screen. Fans have been waiting to see this exciting part of the story brought to life, especially withDemon Slayer’s amazing animation style, for years.
Throughout the story ofDemon Slayer, Tanjiro and his sister, Nezuko, have been central to the plot. They both appear in nearly every episode, and Nezuko has been a huge motivating factor on Tanjiro’sjourney to get revengefor their family - and to turn her into a human again. Throughout their journey, Nezuko has also grown herself, becoming stronger and more important to the plot. So it may come as a surprise for fans who have not read the manga to learn that Nezuko is unlikely to appear in the Infinity Castle arc in any serious capacity. Why? Why willDemon Slayernot have one of the series' main, and most popular, characters in its epic conclusion?
The following contains spoilers for the end of the Demon Slayer manga. Read at your own risk if you are waiting for the anime to be completed.
Manga Debut
Chapter 1
At the end of the Swordsmith Village arc, something incredible happened to Nezuko which was a huge turning point in the story ofDemon Slayer. Throughout the series, even the most powerful demons have had the same weakness - sunlight. If someone fighting the demons can just stay alive and keep them busy until sunrise, no matter how strong the demon is, it will die in the sunlight. The same even goes forKibutsuji Muzan, the Demon King. His only remaining weakness, which keeps him from being perfect and immortal, is sunlight.
Since turning into a demon, Nezuko has shared the same weakness. No matter how powerful she became in her demon form, or how much of her humanity she seemed to be able to maintain, she was still weak to sunlight and it could kill her. That all changed at the end of the Swordsmith Village arc, where it was revealed thatNezuko had overcome this weaknessand could exist in the sun. It was also a turning point for her because she could remove her bamboo muzzle and finally begin to speak again.
No other demon in history was able to evolve in this way, even though all demons were originally humans.Only Nezuko was able to mutateto be safe in sunlight once again. Not being weak to the sun has been Muzan’s goal for over a millennium, and he has been relentlessly pursuing a “cure” to his sunlight sensitivity, believing that it would help him obtain true immortality. When he learns that Nezuko has overcome his one weakness, he becomes obsessed with finding her.
Nezuko’s Safety is Key to Victory
Nezuko Being Captured Would Likely Destroy Humanity’s Chances
As stated above, once Nezuko was able to conquer her sensitivity to sunlight,that made her Muzan’s top priority. His obsession switched from trying to unlock the secrets of the blue spider lilies, which originally cured his human body of disease but failed to give him true immortality, to capturing Nezuko. In Muzan’s eyes, Nezuko had achieved a perfect, eternal body, and if only he could capture her, then he would be able to get the same thing.
Meanwhile, the Demon Slayer Corps has been trying - and failing - to defeat Muzan for centuries.He is simply too powerful, and while they fight the demons that have been created by his influence, they are never able to defeat them at the source. Their only hope of defeating Muzan is to destroy him with his one weakness, sunlight. If Muzan were able to overcome that weakness, then the Demon Slayer Corps and the rest of humanity would likely never have a chance to defeat him.
Thus, keeping Nezuko as far away from Muzan as possible is paramount. If he is able to get a hold of her and understand her powers and her ability, he may be able to replicate them. Muzan is an intelligent creature who has demonstrated an understanding of science, and who has lived for centuries. The chances of him unlocking Nezuko’s power are high, even if it takes time. That is not something that humanity can afford to happen. Thus, despite Nezuko’s incredible strength and abilities, it is in everyone’s best interest that she remain shielded from him and as far away as possible to eliminate the risk of her ever falling into Muzan’s clutches.
Practically speaking, it would be hard to understand why Muzan could not gain Nezuko’s powers if she came to the Infinity Castle with the rest of the Demon Slayers. It would be a very hard plot hole to ignore, and also would make it impossible for Muzan to have a weakness to be exploited. So despite Nezuko being one of the main characters in the series, and a fan favorite at that, it makes sense that she will not make much of an appearance in the Infinity Castle arc. Hernotbeing in the final battle is the key to the main antagonist being defeated, anda happy ending for the series.
