Demon Slayer: The Fear Muzan Had of the Sun Breathing Technique Explained

Overview

Sun Breathing is the premier Breathing Technique, renowned for its potency in combating demons due to its inherent connection to sunlight.
Muzan Kibutsuji harbors a profound fear of Yoriichi Tsugikuni, who almost succeeded in ending his life using the Sun Breathing technique.
To thwart the revival of Sun Breathing, Muzan seeks to annihilate Tanjiro and his family, thus severing any remaining links to this formidable technique.

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The Definition of Sun Breathing
Sunlight: The Ultimate Weakness of Demons
Muzan’s First Encounter with Tanjiro
Muzan’s Lingering Dread

The Definition of Sun Breathing

Sun Breathing stands as the original and most formidable Breathing Technique, serving as the foundation for various styles, including Water, Flame, and Thunder. Its essence replicates the qualities of sunlight, rendering it devastatingly effective against demons.

Historically, Muzan Kibutsuji became a demon after an ill-fated experimental treatment for his illness during the Heian era. Once he discovered the gift of eternal life, he became obsessed with maintaining his immortality. This obsession was challenged when he met Yoriichi Tsugikuni, a legendary Demon Slayer who nearly vanquished him, leaving Muzan instilled with fear of both Yoriichi and the Sun Breathing technique.

Sunlight: The Ultimate Weakness of Demons

Despite his formidable strength, Muzan, like all demons, possesses a critical vulnerability: sunlight. Initially, he was overconfident in his encounter with Yoriichi, believing he could easily overpower the creator of Sun Breathing. However, Muzan’s arrogance backfired; he quickly found himself overwhelmed by Yoriichi’s skills. In a desperate attempt to escape the near-fatal blow, Muzan resorted to shattering his own body into fragments to regenerate later.

The true monster is that man. Not me.-Muzan Kibutsuji

After this harrowing encounter, Muzan experienced fear for the first time, living with the understanding that a Demon Slayer could nearly end his existence. His concerns returned to the forefront when he learned about Nezuko’s ability to walk in sunlight. Determined to eradicate any future manifestations of Sun Breathing, Muzan resolved to eliminate anyone connected to the technique, vowing to destroy all potential heirs of Yoriichi’s legacy.

Muzan’s First Encounter with Tanjiro

The initial meeting between Tanjiro and Muzan occurs in the streets of Akasuka, Tokyo. Recognizing Muzan’s scent, Tanjiro confronts him. In a cunning move, Muzan pretends to be unaware of Tanjiro, transforming a nearby bystander into a demon as a diversion, allowing him to escape. Soon after, he instructs his lower moon demons to eliminate the Demon Slayer bearing the Hanafuda earrings.

Muzan’s Lingering Dread

During this confrontation, Muzan is haunted by flashbacks of his encounter with Yoriichi, recalling the profound fear he experienced on the brink of death. He likely recognizes the Hanafuda earrings Tanjiro wears, which are reminiscent of Yoriichi’s, amplifying his distress as memories of his past resurface.

Tanjiro’s lineage carries the legacy of Sun Breathing, preserved through the Kagura dance—a fact that makes him a significant threat in Muzan’s eyes. Sun Breathing can bypass a demon’s regenerative advantages, further endangering Muzan’s existence. His relentless efforts to eradicate Sun Breathing culminated in the tragic slaughter of Tanjiro’s family, as he aimed to obliterate any remnants of Yoriichi’s heritage and prevent the rise of a new Sun Breathing user.