"Tetsuimaru-san, did you see that?" Musashi asked Tetsuimaru, and when he turned his head, he saw Tetsuimaru frozen in place.
"Tetsuimaru-san?" Musashi called out to her, puzzled.
"Thank you for letting me witness a Bright Red Nichirin with my own eyes…" Tetsuimaru reacted, speaking softly to Musashi.
"Bright Red Nichirin?" Musashi had never heard of this term and felt somewhat confused.
"Most swordsmiths hope to see a Nichirin Sword turn red after forging it. Do you know why?" Tetsuimaru didn't explain the Bright Red Nichirin to him first but instead asked him.
Musashi shook his head; he didn't even know that most swordsmiths hoped to see a Nichirin Sword turn red.
"This is all because of a sentence recorded in the ancient texts preserved in Swordsmith Village: 'The Bright Red Nichirin known as Bright Red Nichirin can suppress demon regeneration.'"
Without waiting for Musashi to say anything, Tetsuimaru continued, "We swordsmiths painstakingly forge Nichirin Swords so that you can slay demons and protect more humans from being harmed by them.
The most troublesome ability of demons is their constant regeneration; unless you sever their necks with a Nichirin Sword or rely on the sun, you cannot kill them at all.
And this sentence in the ancient texts clearly states that this weapon called "Bright Red Nichirin" can prevent demons from regenerating. If such a weapon could be forged, then you would have an advantage in battles against demons.
Therefore, the swordsmiths of Swordsmith Village all hope to forge such a weapon. However, there is only this one sentence about the Bright Red Nichirin, and no one knows how to forge such a Bright Red Nichirin.
After trying for a long time without being able to forge the Bright Red Nichirin mentioned in the records, some swordsmiths speculated that the Bright Red Nichirin was a Nichirin Sword that turned red. After all, the Nichirin Sword is the only weapon that can harm demons and can change color, so this explanation is relatively credible.
After believing this, swordsmiths began to hope that the Nichirin Swords they forged would turn red, which would mean that these blades were very likely Bright Red Nichirins, and the Demon Slayer Corps swordsmen holding them would also gain a slight advantage in battles against demons."
Tetsuimaru slowly explained to Musashi. Her originally impatient personality now seemed very composed. Musashi listened to her explanation, and respect for these swordsmiths arose in his heart.
Perhaps they did not fight demons on the front lines, but it was precisely because of them that the Demon Slayer Corps swordsmen could slay demons. They were also fighting against demons and protecting humans in their own way.
They hoped that the Nichirin Sword would turn red, which was actually hoping that the Demon Slayer Corps swordsmen would survive in battles against demons. Their hearts were also concerned about the Demon Slayer Corps swordsmen; swordsmiths and swordsmen are comrades-in-arms on different battlefields.
"But soon this speculation was overturned. Swordsmen of Flame Breathing have a high probability of making their Nichirin Sword turn red, but such a Nichirin Sword does not have the ability to suppress demon regeneration.
After realizing this, swordsmiths regarded the sentence recorded in the ancient texts as an unfounded legend, but thinking about that slim possibility, swordsmiths still hoped that the swordsmen holding Nichirin Swords could make their Nichirin Sword turn red, after all, the only record of the Bright Red Nichirin was its color."
Tetsuimaru explained the reason to Musashi, and Musashi understood her words.
However, Tetsuimaru's words were not finished. She continued to look at Musashi and said, "After seeing you turn the black Nichirin Sword red just now, I had an idea. The Bright Red Nichirin just now must be the Bright Red Nichirin recorded in the ancient texts.
And the Bright Red Nichirin is a Nichirin Sword, but making a Nichirin Sword into a Bright Red Nichirin is not simply by making it red with one's own Breathing Technique, but rather the wielder using some method to unleash the power of the sun contained within the Nichirin Sword.
The raw materials used to forge Nichirin Swords are Scarlet Crimson Iron Sand and Scarlet Crimson Ore, mined from the mountain closest to the sun. Both are ores that can absorb sunlight.
Therefore, the Nichirin Swords forged from them can harm demons, but the power of the sun contained in the ore, absorbed over many years, has not been fully unleashed.
And the Bright Red Nichirin is very likely to have turned crimson and gained the ability to suppress demon regeneration precisely because the power of the sun contained in these two ores was unleashed, after all, the sun is the natural enemy of demons."
How amazing…
Tetsuimaru's analysis left Musashi somewhat astonished. He also saw Tetsuimaru's understanding of ore and her superb forging skills from it; otherwise, she would never have been able to make such an analysis.
"When I faced Lower Moon Two not long ago, after I cut off its limbs, it indeed could not regenerate them." Tetsuimaru's words also made Musashi recall some details of that battle. Everyone said that demons could regenerate quickly, but he seemed to have never seen a demon regenerate since joining the Demon Slayer Corps.
Of course, part of the reason was that demons couldn't last more than a few moves in his hands.
Upon hearing Musashi's words, Tetsuimaru was not surprised. She was very confident in her conjecture.
"So, if I can figure out the conditions for me to turn the Nichirin Sword red, then the Demon Slayer Corps swordsmen can become even stronger!" Musashi quickly thought of this, feeling a little excited.
"I'll research it now!"
Musashi said, holding his Nichirin Sword, intending to start experimenting. Although he could turn the Nichirin Sword into a Bright Red Nichirin, it was as simple to him as opening his mouth when eating or taking a step when walking. He still didn't know the principle behind it.
"Wait a moment." However, Tetsuimaru stopped him at this moment.
Musashi turned his head somewhat puzzled, seeing Tetsuimaru extend her hand to him.
"First, give me the Nichirin Sword so I can engrave the characters on your Nichirin Sword before anything else. I still have to rush back to the village before dark."
Tetsuimaru spoke to Musashi.
"Alright, then I'll trouble you." Musashi understood, sheathing the Nichirin Sword in his hand and handing it to Tetsuimaru.
"Don't worry, I'll return the blade to you as soon as possible, it won't delay your matters. If you can truly figure out how to turn the Nichirin Sword into a Bright Red Nichirin, it will be a good thing for all of us." Tetsuimaru took the Nichirin Sword and assured Musashi.
Then she went to get her tools.
In less than an hour, the Nichirin Sword was back in Musashi's hands, but now the blade had the four characters "Demon Extermination" engraved on it.
"Alright, my work is done, it's time to go. Finally, I wish you can find a way to turn the Nichirin Sword into a Bright Red Nichirin. Goodbye."
Returning the Nichirin Sword to Musashi's hand, Tetsuimaru said to Musashi.
She was very satisfied with her experience at the Demon Slayer Corps Headquarters this time, and her favorability towards Musashi also increased significantly. While engraving the characters on Musashi's Nichirin Sword, she found that the Nichirin Sword had no chips or anything, and was still as good as new, which showed that its wielder cherished it very much.
Although swordsmiths also knew that it was normal for Nichirin Swords to wear out in battles against demons, seeing her hard work intact still made her very happy.
"Thank you for your blessing, goodbye, Tetsuimaru-san."
Musashi thanked Tetsuimaru and waved goodbye to her with a smile.
Tetsuimaru said nothing more, put on her straw hat, and turned to leave.
I should also try my best to find a way to turn the Nichirin Sword into a Bright Red Nichirin…
After watching Tetsuimaru leave, Musashi also turned and walked towards the training ground of the Demon Slayer Corps Headquarters.
At the same time, three young boys embarked on their journey to Mount Natagumo…