The battle between Tanjiro Kamado and Daki became existential in the sixth episode of Demon Slayer: Kimetsu no Yaiba, in the “Entertainment District” arc. Dangerously enraged by Daki’s violent slaughter of an entire city block, Tanjiro’s calm and icy demeanor as he sliced Daki into pieces stirred a memory in the high-ranking demon – except that he belonged in Musan. Seeing the vision of a man who appeared to be a Sunbreath user, Daki had the same question as the audience: who was this man?
Every demon that walks the Earth has a part of Muzan Kibutsuji’s genetic heritage in their body. As the progenitor of demons, it is only through his blood that a human being can be transformed into a demon. This allowed Muzan to have omniscient knowledge and omnipotent control over his demons, but the memory Daki experienced is new information regarding the extent of his master’s influence. This particular memory, however, is probably something Muzan would have preferred not to see, even by one of his most trusted creations.
As Tanjiro coldly condemned Daki and his way of treating human beings, the High Ranking Demon was struck by the memory of another man giving a very similar message, but not to her. Daki quickly identified the memory as Muzan’s, in which a man with the same auburn hair, Hanafuda curls, and forehead scar as Tanjiro gave him an equally disturbing speech. Given his many similarities to Tanjiro, it’s clear that the mysterious man was a companion to Sun’s Breath, Demon Slayer’s original and most powerful breathing style.
There was a brief flash of the man charging forward, sword in hand, implying that he indeed fought Muzan. If Daki’s sudden tremors are to be believed – which she confirmed came from memory and not from herself – this fight is an unpleasant memory for the Demon Ancestor. It’s clear that this mysterious Breath user failed to kill Muzan, but the fact that Muzan’s cells reacted so strongly to this reminder makes it seem like a close call. Given the raw strength of Tanjiro’s Sunbreath against Daki, if the mysterious Sunbreath was a master, it makes sense that he could have inflicted vicious wounds on Muzan.
As for the identity of this mysterious Breath user, only contextual clues allow us to draw any conclusion. According to Shinjuro Rengoku, a forehead scar, like the one Tanjiro and the mysterious man both bear, is the mark of a Breath user. Given that Muzan is 1,000 years old and the Sunbreath appears to have been lost outside of the Kamado family, this is likely a fairly old memory. Considering the Sunbreath is the original breathstyle, and this man seems to have used it to hurt Muzan years ago, Daki may have seen the face of the very first breathstyle user.
When Muzan launched his first attack on Tanjiro, he asked his demons to search for “the boy with the Hanafuda earrings”. This memory confirms that the villain does indeed know the meaning of those earrings, and explains why he wants Tanjiro dead but didn’t do it himself. Muzan Kibutsuji, the Original, Progenitor and King of Demons, might actually be afraid of a young charcoal burner who just wants to turn his sister back into a human. Let’s hope Tanjiro survives his final confrontation with death in one piece so he can continue to master the Hinokami Kagura, because the very idea of Sunbreath’s existence strikes fear into the heart of the most powerful demon. of Demon Slayer.