I didn’t realize Muzan’s Infinity Castle was more than a hideout until it started moving like his own mind

The Demon Slayer Infinity Castle is an interesting structure in the animanga series. It was first introduced in season 1 when Muzan had summoned all the Lower Moon demons at the time. This was following Rui's death at Mount Matagumo, which angered the Demon King.

Muzan didn't care about other demons or how they felt. He only wanted one thing, and that was results. However, I realized that the Infinity Castle is more than just a fortress for him and his demons.

Its purpose and representation go beyond that of protection. In fact, a closer look into the structure will not only reveal more about it, but also show its connection to Kibutuji Muzan in the Demon Slayer series.

Disclaimer: This article is based on the author's opinion and contains spoilers from the Infinity Castle arc manga chapters.

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Demon Slayer: The Infinity Castle and its representation of Muzan's psyche

I first analyzed the structure and the function of the Infinity Castle. As mentioned earlier, this is a demon stronghold, and Muzan is often sequestered in some corner conducting research. The entire castle is controlled by Nakime, the demon who plays the Biwa. Her Blood Demon Art allows her to use the strings of the Biwa to play notes, which in turn manipulate the castle's orientation.

We can see the building change its orientation, shape, and the size of the rooms rapidly in the Infinity Castle arc. Now let's compare this to Muzan's state of mind.

There is a considerable amount of instability. Everyone is expendable to him, and he doesn't trust a single person. Furthermore, we can see that Kibutsuji Muzan likes to be in control of everything. When he charts out a plan, he wants every step completed in a particular manner.

Kibutsuji Muzan as seen in the anime series (Image via Ufotable)

His anger towards the Upper Moon demons highlighted his controlling nature. He is frustrated with them for their failures. He wants to find the Blue Spider Lily, and the death of their peer angered him further.

The Infinity Castle's constant flux and need to be controlled reflect Muzan's personality in the anime and manga series. Furthermore, the architecture of the building is another interesting element that connects the castle to Muzan.

The castle's interiors could have been low-key and purely functional in the Demon Slayer series. After all, its purpose was to safeguard demons, and Muzan would use it to perform experiments. However, the sheer grandeur of the interiors cannot be overstated.

It almost seems like the interiors of a shrine dedicated to an important God. Muzan considers himself to be the most superior form of being. One can observe a clear God complex in this character, which is once again highlighted through the castle.

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Conclusion

I believe that the castle is the perfect metaphor for Muzan's unstable mental state. The ever-changing nature of the building not only has a functional purpose but also drives home the point that Muzan is unpredictable. It is difficult to assess what he would do in any situation.

Furthermore, the grandeur of the building indicates his superiority complex, which has been shown in simpler forms during various points in the Demon Slayer series. This is how Koyoharu Gotouge highlighted Muzan's mental state and psyche in a much more complex yet subtle way that some fans might have missed.

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