These conditions allow the ore to be irrigated by sunlight, which is the only major weakness facing demons. It’s a travel purpose and part of Demon Slayer’s training to get the mine used to build their weapon. Once formed, these Nichirin blade swords always absorb sunlight, allowing them to be the only device capable of killing demons. Nichirin blades are therefore the main weapon of the Demon Slayer Corps and an essential tool.
Moreover, an even stronger version of this weapon, the Crimson Red Nichirin blades, can be achieved by raising the temperature of the sword to true levels, striking two Nichirin blades together in the correct manner, or applying the action the right form of Demon Blood intense art. The Crimson Red Nichirin sword is even more effective because the heat allows demons to be destroyed at the molecular level, which means that levers or wounds from this blade do not heal like the normal type.
Why do swords take on different colors?
Nichirin blades are also referred to as “Color Changing Swords” and the reason for this is that the blades take on a specific color when they are first drawn by their Demon Slayer owner. By permission, this color transformation is not mandatory and the Demon Slayer must already be at skill level to trigger the process in the first place. This makes the act even more special and an easy signal for when Demon Slayer starts to increase in strength.
As for the color transformation itself, it should be a symbol of the overall personality, approach and energy that is within each Demon Slayer. For example, someone with a fiery and aggressive solution would probably see their sword turn orange or red, but a Demon Slayer full of love might get a pink blade. These unique colors make the swords function as an extension of the Demon Slayer and their values.
Another aspect of loneliness that is present with each sword is the special hand guard that protects the wielder from his blade. These hand guards do not have special powers and have more control over the owner of the sword, but they are still a fun element that translates to a Demon Slayer that looks like a talent. Tanjiro’s wristband is a subtle black ring with a wheel beauty, but others like Shinobu and Mitsuri’s shamrock-shaped flower protectors are much more creative and reflect their Hashira art.