Muzan's true reason for hating Tamayo in Demon Slayer may lie in her unique skills

Muzan Kibutsuji, the primary antagonist of Demon Slayer, is notorious for his ruthless domination over demons and his obsession with absolute control. Among the many demons who broke free from his influence, Tamayo stands out as a particularly intriguing figure.

Her betrayal and defiance undoubtedly angered Muzan, but his true hatred for her may stem from something deeper, her unique skills. Tamayo not only freed herself from Muzan’s curse but also developed abilities that rivaled his own, including the power to create demons and work toward a cure for the demon curse. This exceptional combination of talents likely threatened Muzan’s supremacy.

Tamayo learned from Muzan’s mistakes in the Demon Slayer series

Tamayo as shown in the anime series (Image via Studio Ufotable)

Tamayo’s transformation of Yushiro into a demon is a fascinating mystery that sparks many questions. While it may seem straightforward, the complexity lies in understanding how she managed it, why it took her 200 years, and what it reveals about demon biology and her abilities.

Tamayo’s history with Muzan provides key context. She once worked under him, possibly as a doctor, assisting in his research to conquer the sun. Muzan, ever confident in his power, might not have realized that sharing even fragments of knowledge about demons could backfire.

By revealing that the demon transformation process was biological and hinting that demons could evolve, Muzan inadvertently opened the door for Tamayo to question his methods.

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

Tamayo likely deduced that demons were created through an incomplete medicine, which gave her the foundation for believing a cure was possible. Her perspective as a former demon turned against Muzan gave her unique insight, far beyond what members of the Demon Slayer Corps, like Shinobu, could imagine.

Tamayo's 200-year journey to transform Yushiro in Demon Slayer series

A snapshot of Tamayo (Image via Studio Ufotable)

After leaving Muzan, Tamayo began studying demon biology in earnest. Rather than immediately searching for a cure, she likely focused on understanding how demons were created. This research led her to experiment with her own body, allowing her to develop modifications that let her survive on minimal blood. She may have also discovered her Blood Demon Art during this period.

It’s plausible that Tamayo eventually succeeded in creating a crude version of the demon-transforming drug. This substitute, unlike Muzan’s, didn’t require the Blue Spider Lily. Instead, it likely relied on her Blood Demon Art. This suggests that her ability to create demons stemmed from her unique powers.

Yushiro as shown in the anime series (Image via Studio Ufotable)

However, the process was incredibly taxing. Tamayo’s abilities, while impressive, required immense energy, which could explain why it took her two centuries to turn Yushiro into a demon. While her other Blood Demon Art techniques seemed relatively low-cost, creating a demon would have been a far more significant feat, requiring great preparation and strength.

The poetic justice of Tamayo’s abilities in Demon Slayer series

A snapshot of Kibutsuji Muzan (Image via Studio Ufotable)

There’s a sense of poetic justice in Tamayo’s power to create demons. Muzan, who prided himself as the sole source of demon creation, would have despised the idea of someone else wielding that same ability.

Yet, it was this very power that allowed Tamayo to ultimately help create a cure for demons. Her collaboration with Shinobu in developing the demon-reversing medicine likely relied not just on her medical expertise but also on her Blood Demon Art. Without it, the cure might never have been possible.

A snapshot of Yushiro (Image via Studio Ufotable)

Another layer of irony lies in Yushiro’s eventual fate. According to some theories, it’s suggested that over time, Yushiro’s demonic blood might thin, allowing him to age and live as a human again. If true, this possibility underscores the idea that Tamayo’s Blood Demon Art wasn’t just about creating demons but also about giving them more time. This outcome aligns with Tamayo’s ultimate goal: to undo the harm demons cause and reclaim their humanity.

Final thoughts

Kagaya Ubuyashiki (Image via Studio Ufotable)

Tamayo’s transformation of Yushiro into a demon was likely a combination of her Blood Demon Art and her deep understanding of demon biology. The process took centuries due to the immense energy required and her meticulous research. Her ability to create demons, derived from Muzan’s own knowledge, ultimately became the tool she used to find a cure for the demon curse.

This transformation was not just a scientific breakthrough but a deeply symbolic act, showcasing Tamayo’s triumph over Muzan’s oppression. If Yushiro’s blood does thin over time, it would complete the poetic cycle of Tamayo’s efforts, granting him the life she always wished demons could reclaim.