Demon Slayer fans may have missed the biggest twist involving Tanjiro's exploding blood sword

Demon Slayer season 3 sees Tanjiro on a quest to find a replacement Nichirin Blade for himself, leading the protagonist on a journey to the legendary Swordsmith's Village. Meanwhile, Muzan, the Demon King, seeks revenge for the deaths of two Upper Moons, Daki and Gyutaro, by dispatching his other two Upper Moon demons to attack.

With only a few more episodes left of the Swordsmith Village arc, the revelation of the Exploding Blood Sword, also known as the Bright Red Nichirin Sword, has generated immense excitement among both anime-only fans and manga readers. However, fans recently made an intriguing discovery when looking back at the first season. It seems that an earlier appearance of the red blade can be found in season 1.

Disclaimer: This article contains spoilers from the Demon Slayer series.

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Demon Slayer fans seem to find the Exploding Blood Sword in season 1

What is the Red Nichirin Blade?

As fans of Demon Slayer are aware, the Nichirin Sword is of utmost importance in the series since it is the only weapon capable of decapitating Demons. A colored variant of the Nichirin series is the Exploding Blood Sword or Bright Red Nichirin Sword, which makes an appearance in Demon Slayer season 3 episode 5.

It is activated when Nezuko, with her Blood Demon Art, intentionally allows her blood to trickle onto Tanjiro's blade. Due to the combination of her powers and Tanjiro's own Demon Slayer Mark, the Nichirin sword catches fire and transforms into a red flaming blade.

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What led to the appearance of a red blade in Demon Slayer season 1?

Fans of the Demon Slayer anime will remember the iconic fight scene between Tanjiro and Rui in season 1. During their intense battle, Tanjiro eventually tapped into the advanced form of Water Breathing, which gave him the power to effortlessly slice through Rui's threads.

At the same time, Nezuko, who had fallen unconscious while entangled in Rui's webs, awoke and unleashed her Blood Demon Art. Her blood burst into flames that incinerated the threads and saved Tanjiro from imminent danger. However, in the process, a few drops of Nezuko's blood also stained Tanjiro's Nichirin Sword. In the anime, this turns his sword blood red in color.

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Does the Red Nichirin Blade appear in season 1 of the anime

Whether the Bright Red Nichirin Sword or the Exploding Blood Sword made its debut during the first season is a hotly debated subject. Some fans have said that the spurt of Nezuko's blood triggered the red blade for a short period, which holds some validity. This logic could be used to rebut arguments such as the redness of the sword is just the result of the artistic choices made in coloring an impact frame or the claim that the real blade should not have allowed Rui to rejoin his head.

There is no official confirmation on this matter, particularly if one considers the manga as the sole canon. However, the anime, with the benefit of hindsight, can easily leave some surprises in for the fans. Additionally, many believe that the anime contributes to the canonicity of the manga, thereby establishing the appearance of the Exploding Blood Sword during season 1 as legitimate, albeit as an undeveloped concept.