Most Demon Slayers don’t have the kind of superhuman strength and abilities that demons do, putting them at an inherent disadvantage. Part of why a Demon Slayer’s training is so daunting is because it must prepare potential candidates for the dangerous world they’re joining. The same applies to the Final Selection, which thrusts applicants into an actual life-or-death situation with an incredibly low survival rate.
In order to close the gap, Demon Slayers are equipped with Nichirin Swords. These unique weapons are one of the few ways that a human can kill a demon directly. Nichirin Swords are an invaluable tool in the fight against demons, and that’s just one of the many reasons why they’re so special within the Demon Slayer universe.
How Nichirin Swords Are Made
What makes Nichirin Swords so effective against demons has a lot to do with how they’re made. Rather than use steel when forging them, swordsmiths use a special kind of ore that gives them the properties needed to fight demons.
Nichirin Swords are crafted using Scarlet Crimson Ore as well as Scarlet Crimson Iron Sand. Both absorb a significant amount of sunlight throughout a given year, and so are the ideal crafting material given demons' weakness to the sun.
Once they’ve made it through the Final Selection, Demon Slayer recruits get to choose their own ore which is promptly sent to the Swordsmith Village. From there, a swordsmith will craft and personally deliver the sword themselves.
Different Variants & What They Symbolize
There are a number of different Nichirin Sword variants that exist in the Demon Slayer world. Aside from each character having their own personalized handguard, Nichirin Swords also take on different colors depending on the wielder. This only happens if the wielder is skilled enough to trigger this change, making those who use these variants among the most prominent in the corps.
There have been 14 different color variants shown throughout the series so far, each one representing the Breathing Style of its user. These range from more straightforward designs, like Giyu’s blue-colored sword representative of his Water Breathing, to more abstract ones like Shinobu’s lavender/blue and Inosuke’s indigo/grey colored swords, representing Insect and Beast Breathing respectively.
In rare cases, as with Tanjiro, Nichirin Swords will turn black. This is a highly uncommon color and one that is thought to be a sign of misfortune for those who wield it. The belief being that because there isn’t much information on these weapons, their users died young before anything significant could be learned about them.
Though this initially seems like a bad omen for Tanjiro, black Nichirin Swords are later revealed to be associated with Sun Breathing. This makes the black-colored Nichirin Sword an equally rare variant and like the Breathing Style, it represents, an incredibly useful tool in the fight against demons.
The Bright Red Nichirin Sword
A colored Nichirin Sword is a sign of an adept Demon Slayer, but there exists a technique that signifies an even greater level of proficiency among members of the corps. The Bright Red Nichirin Sword can only be used by a select few and stands as the most effective way to defeat a demon outright.
Only those with the Demon Slayer Mark or extremely powerful Hashira have been known to make use of this ability. Thanks to their Sun Breathing, Tanjiro and Yoriichi can access this power organically while engaged in combat, whereas others have done so through intense focus and strength of will.
When using this power Nichirin Swords can hinder a demon’s healing abilities, similar to the effect that sunlight has on them. It has been shown to be useful against Muzan himself, though not strong enough to permanently affect his ability to heal.
Wisteria flowers and poisons have been shown to be just as effective in combating demons, as illustrated by their use in the Final Selection. However, Nichirin Swords allow Demon Slayers to be more active in their activities, while also allowing them the opportunity to defend themselves against incredibly strong foes. The effectiveness of the blade depends on the skill of the user, but they stand as the best tool Demon Slayers have in their fight against evil.