'This sword...'
As soon as Riezel gripped the new Hermit, which had become a Nichirin Sword, an expression of astonishment involuntarily crept onto his face.
It couldn't be helped.
'So heavy and hot...'
Surprisingly, the Nichirin Sword he now held felt as heavy as a war hammer and radiated intense heat that reached the boiling point of water, 100 degrees Celsius.
Such a sword would be impossible for an average swordsman to even hold by the hilt.
'With this weight, Lightweight probably won't be much use when I use this sword in the future...' Riezel sighed and lowered the sword.
*Pssst—*
As the sword descended, before it even touched the ground, it emitted a sizzling sound, leaving a small blackened mark on the ground.
Riezel was momentarily stunned and quickly raised the sword again, lost in thought.
After a moment of pondering, Riezel used structure system magic to create a block of iron and threw it into the air.
Watching the iron block in the air, Riezel quickly swung the sword.
*Swish!*
In the next moment, the blade of the sword sliced through the iron block as if it were butter, splitting it in two effortlessly and causing it to fall to the ground. However, what was shocking was that the cut edges still emitted a red glow and smoke.
Upon seeing this, Riezel was pleasantly surprised.
'So sharp... No, not sharp...'
Riezel realized that the reason Hermit could cut through the iron block so easily was because of the high temperature condensed on its blade. In this high-temperature state, its cutting power became extremely fearsome.
It was more accurate to say Hermit burned through the iron rather than cut it.
With such a high temperature, logically, Hermit's blade should have been affected too. Yet, due to Hermit's possession of the Durandal attribute, its blade miraculously maintained its quality and appearance.
'Without a doubt, the performance and power of this new Hermit definitely surpass Fool's...'
Riezel knew that the new Hermit was undoubtedly first-class special equipment. He couldn't believe that the new sword he had refined with magic was so perfect on his first try!
'Is it because I triggered the imaginary system when using magic or did some chemical reaction occur after Hermit fused with the gemstone containing the purest essence of many Scarlet Crimson Iron Sands and Scarlet Ores?'
Riezel wasn't entirely sure, but he knew one thing—he might have obtained a special and incredible Nichirin Sword.
'Let's go try out this sword.'
Riezel couldn't hold back his curiosity anymore and quickly left the warehouse with Hermit in hand.
===
In the rear of the Rengoku family's residence, there was a small mountain that looked like the family's backyard, forming a large expanse of forest.
As Riezel entered the forest, he observed his Nichirin Sword, Hermit.
At this moment, Hermit's blade was changing color.
Any Demon Slayer knew that this was a characteristic shared by all Nichirin Swords.
Nichirin Swords, also known as the 'Color Changing Katana', would change color according to the master of the sword, reflecting the breathing style suitable for the user.
For those suited to Water Breathing, when they gripped a Nichirin Sword, its blade would turn blue.
For Thunder Breathing, it was golden.
For Flame Breathing, it was red.
For Wind Breathing, it was green.
For Stone Breathing, it was gray.
Like Kyoujurou, his Nichirin Sword's blade was red, while Tanjirou's was black.
Black Nichirin Sword was a very rare and uncommon type of Nichirin Sword, and no one knew which breathing style a swordsman suited to it would use.
However, Riezel knew that users of black Nichirin Swords had extremely high compatibility with Sun Breathing.
Yoriichi's Nichirin Sword, with its black blade resembling obsidian, only turned red during battle.
As for Riezel's Nichirin Sword, under his gaze, it slowly turned black.
Yes, his Nichirin Sword also had a black blade.
However, the crack-like texture on the blade did not disappear; instead, it became brighter and more vivid.
When one looked at the black on the blade, it was an extremely thorough, deep abyssal black, making it feel like staring into a black hole.
"Huuu..."
"Haaa..."
Riezel adjusted his breathing before suddenly swinging his sword forward.
*Whoosh!*
A great fire burst out.
Amid the terrifying heat, flames suddenly descended from the sky with Riezel's swing, smashing the ground into pieces.
Before long, the wildfire raged through the forest, igniting countless trees in an instant, and turning the surroundings into a sea of fire.
"Decompose."
Riezel immediately used decomposition magic, causing crimson waves to sweep through the entire forest like a hurricane, breaking down the flames into nothingness.
However, the aftermath of the wildfire still remained.
Charred smoke billowed, blackened traces spread all over the ground, and the partially burnt trees made the area look like the aftermath of a fire.
Only then did Riezel sit down on the ground, looking around the surroundings, and then at Hermit, which was now wrapped in flames, gradually smiling.
'Its power is indeed impressive, and on top of that, it really matches well with Sun Breathing...'
Although this new Hermit somewhat limited his Lightweight development ability, it enhanced his attack power and explosiveness.
'From now on, Hermit will be the exclusive weapon for Sun Breathing.'
With that thought in mind, Riezel began experimenting with his other abilities in the mountains.
However, after some attempts, Riezel stopped and furrowed his brow.
There was both bad news and good news.
The bad news was that he couldn't use magic while using Sun Breathing—or, to be precise, he couldn't use enchant magic like 'Ariel'.
Perhaps it was because the evolved Sun Breathing stimulated the massive magical energy within his body, activating it and incorporating it into his blood flow, which caused a conflict with the magical energy flow affected by Ariel.
Or perhaps it was because Sun Breathing and Ariel had different attributes. If both were used simultaneously, the flow of magical energy within his body would become chaotic, causing issues with the circulation of Sun Breathing.
Because of this, not only could he not use Ariel or protection magic like Raumure to enhance his END and AGI, but he couldn't use any magic that directly affected his body.
Other types of magic had no impact, as long as they didn't affect his body, such as magic that directly enhanced his strength or speed.
Clearly, this meant that once he used Sun Breathing, he couldn't add any other amplifying strengthening magic, support magic, or auxiliary magic.
However, the good news was that by using Ariel and Wind Breathing from the five fundamental breathing styles simultaneously, not only did the effect of Ariel strengthen, but the burden on his body also decreased significantly.
'Is it because Wind Breathing and Ariel have similar attributes, making them highly compatible?'
Riezel was somewhat found the reason behind it.
Not only did Wind Breathing strengthen Ariel, but using a breathing style also automatically increased his physical ability, greatly enhancing his body's endurance. As a result, the burden caused by Ariel was significantly reduced when he used Wind Breathing.
Riezel felt that the similarity in wind attributes also played a role, explaining why the burden caused by Ariel on his body was not as significant as usual when he used Wind Breathing.
Otherwise, relying solely on the enhancement of endurance by Wind Breathing, it would be far from easy to fully withstand the burden brought by an overpowered enchant magic like Ariel.
It was indeed a blessing in disguise.
'Although Sun Breathing and Ariel can't be used at the same time, I can split them into two modes for future battles, right?'
Riezel immediately had an idea.
'Hermit pairs nicely with Sun Breathing, allowing me to fight stably across a level. In this mode, my overall abilities are at their strongest, enough to compete with opponents ranging from low to mid Level 7.'
'Fool, on the other hand, can be paired with Ariel and Wind Breathing. It maximizes the effect of Lightweight, boosting AGI and DEX, two crucial basic abilities for Ariel. With this mode, I should surpass the speed of an ordinary Level 7.'
If only Ariel was used, the current Riezel would be able to comfortably defeat the strongest Level 6, not too far from Level 7 combat power.
Moreover, Wind Breathing could strengthen Ariel's effect and mitigate its burden, likely granting Riezel the strength to rival Level 7. Using Fool in this state, fully maximizing the effect of Lightweight, when only calculating DEX and AGI, ordinary Level 7 wouldn't stand a chance against him.
On top of that, Riezel could still further enhance his AGI using Raumure. In this state, his other basic abilities might barely reach the limit of Level 7, but his AGI would significantly surpass this, reaching the limit of Level 7.
With this arrangement, Riezel could choose which mode to use based on his opponent.
'Strong attack mode is when I use Hermit as the main weapon with Sun Breathing.'
'Fast attack mode is when I use Fool as the main weapon with Wind Breathing, Ariel, and Raumure.'
'Yeah, this seems doable.'
With that in mind, Riezel took Fool out of the storage space and gripped it in his hand. With a thought, a word soon appeared on its hilt that read 'Fool'.
It wasn't added for aesthetics or to engrave a crest but to prevent its loss. Whether it was the word 'Hermit' or 'Fool' in their hilts, both served as marks for his summoning magic.
As long as these marks didn't disappear, Riezel could summon these two weapons to his hand through magic. In this way, even if they accidentally slipped away, he didn't have to worry about losing them.
Naturally, it was one of the many simple magics taught by Yuri, still seemingly unimportant but quite practical.
As he finished, Riezel put Fool back into the storage space and kept Hermit in his hand.
At this moment, Riezel planned to create a scabbard for Hermit, as the previous one was completely unsuitable for further use.
However, since Hermit's blade temperature was relatively high, it was challenging to create a scabbard capable of bearing it.
Regardless, Riezel had no choice but to do it, as he truly cherished his new Nichirin Sword dearly.