*Rumble!*
With this rumbling sound, the last Autonomous Guardian charging out of the ancient city finally collapsed.
Its body was riddled with wounds—not only had its head been blown off, but two of its limbs were also severed. Deep, gruesome gashes covered its body, making it easy to imagine the brutal beating it had suffered before finally falling.
Meanwhile, the knights of the Mavros family stood around the fallen Autonomous Guardian, breathing heavily while keeping their bodies tense—their eyes remained fixed on the city entrance as if expecting another Guardian to appear at any moment.
Riezel, whose eyes shimmered with a transparent glow and who hovered in midair, observed the city momentarily before descending and speaking up.
"Alright, the fight's over. I don't see any more of them coming out."
Upon hearing this, everyone was stunned for a moment before, as if a taut string in their hearts had finally snapped, each and every one of them collapsed onto the ground, gasping for air.
"It's finally over..."
"Yeah..."
Axel and Diego also slumped onto the ground, drenched in sweat.
"Fifty-four..."
Kaiser didn't collapse, but he did drop to one knee while murmuring these words.
A total of fifty-four Autonomous Guardians had charged out of the city, only to be taken down one after another. Even though they had managed to defeat them, fighting fifty-four Guardians in succession without rest had left them utterly exhausted.
It wasn't just the swordsmen whose stamina was nearly depleted—even the magicians had almost no magical energy left as each of them sat on the ground right now, looking completely drained.
Seeing this, Raven, with sweat dripping from his forehead and slightly out of breath, sheathed Rebellion before giving a command.
"Rest up. Recover your stamina and magical energy."
After giving this brief command, Raven walked over to Nibald's side and started speaking with him in a low voice.
Nibald, unlike the others, was still in good condition since the fierce battle just now seemingly hadn't drained him much at all.
Evidently, with the vast magical energy of a Strategic-Class Magician, using it for Combat-Class Magic barely put a dent in his reserves, so Nibald remained completely unfazed, appearing as the only one besides Riezel who looked calm and composed. He hadn't even dispelled his summoned wyverns, letting them continue circling in the air above his head.
As for Riezel, he was sitting nearby, supporting the little princess, Lizbeth.
"You okay?"
Asking this, Riezel chuckled softly as he looked at Lizbeth, who sat on the ground in a duck-like sitting position instead of collapsing roughly like the knights.
"I-I'm okay..."
Lizbeth, seeming a little embarrassed, tried to stand up, but Riezel stopped her.
"Your stamina's pretty drained, so rest for a bit first. Focus your awareness more and refine your breathing."
Lizbeth immediately followed Riezel's instructions and began adjusting her breathing.
"Focus more, refine it further, and don't mess up the rhythm. Keep this intensity steady, and don't let your breathing change with your body's condition."
Riezel extended a finger and tapped Lizbeth's forehead.
"Remember, the key to a breathing style is maintaining, sustaining, and concentrating. If you master that, you'll eventually make it instinctual, keeping it up 24/7 without effort."
"When that happens, not only will your stamina improve, but your blood circulation, metabolism, and other bodily functions will also enhance. You'll become stronger, last longer in battles, and even heal injuries to some extent—restoring your stamina faster and stopping bleeding."
"Such a condition is known as 'Total Concentration - Constant'."
"Make sure to practice it well, got it?"
Listening to Riezel's explanation, Lizbeth nodded repeatedly, taking everything in like an obedient student.
"So? How was it using Love Breathing in battle for the first time?" Riezel asked with raised eyebrows.
Lizbeth thought for a moment before answering honestly.
"It felt great, but when switching to offense, it was kind of hard. Both the strength and the slash angles felt a bit off from what I imagined..."
Riezel wasn't surprised at all by her answer.
"It's probably your weapon. I mean, the one who created Love Breathing used a sword as flexible as a whip that was made specifically to complement the sword forms of Love Breathing, so using Moslow for those sword forms naturally feels off."
Kanroji Mitsuri's specially crafted Nichirin Sword, a retractable sword that could coil and fit into a scabbard, wasn't just whip-like in flexibility but also had incredible durability.
Most of Love Breathing's sword forms were designed to cut through enemy attacks, bypass defenses, and overwhelm opponents with dazzling offensive maneuvers. When combined with Mitsuri's flexible sword, these forms could execute attacks while simultaneously defending, creating a perfect balance of offense and defense.
Right now, Lizbeth was using Moslow, a beautifully crafted, standard Western-style sword, to perform Love Breathing's sword forms, so feeling difficulties when switching to offense, along with misaligned strength and slash angles, was only natural.
Regardless, this wasn't a big issue.
"Luckily, this breathing style is super flexible and adaptable." Riezel continued his explanation. "You just gotta adjust it based on your own way, conditions, and habits, and you should be able to get it right."
In the world of Demon Slayer, a lot of Demon Slayers would tweak their combat style to some extent based on their own conditions and habits.
For example, a user of Stone Breathing, the so-called strongest member of the Demon Slayer Corps, Himejima Gyoumei, wielded a Nichirin Sword that was actually a massive axe and flail connected by a long chain, which consisted of insanely high-purity Scarlet Crimson Iron Sands, making it absurdly heavy.
In the original work, even Kokushibou admitted that such a weapon was nearly impossible to find, even in the Sengoku period, which proved that the swordsmen who first practiced Stone Breathing didn't originally use a weapon like that.
Riezel didn't believe that every Demon Slayer in the Demon Slayer Corps who trained in Stone Breathing used such a unique weapon as Gyoumei. Unlike other derivative breathing styles, Stone Breathing was one of the five fundamental breathing styles, so there was no shortage of practitioners.
With that in mind, anyone would assume that Gyoumei's weapon was something he adapted for himself after adjusting his breathing style's sword forms to fit his needs.
Naturally, the same applied to the other Hashira.
Aside from Rengoku Kyoujurou, Tomioka Giyuu, Shinazugawa Sanemi, and Tokitou Muichirou, all of them wielded Nichirin Swords with wildly unique designs.
However, while that was fine for them, did every swordsman in the Demon Slayer Corps who trained in the same breathing styles also use such unconventional weapons?
Of course not.
For this reason, it was common for a Demon Slayer to modify their weapon based on their own needs, conditions, and habits, then adjust their breathing style's sword forms accordingly, so they could make it more suitable for themselves and fully unleash its potential with the weapon they were best at using.
Meanwhile, when a Demon Slayer found that their breathing style couldn't be adjusted to fully match their abilities or maximize their potential, they would take another path—developing a branch breathing style based on their original one, making it more suited to them.
Breathing styles were just that adaptable and flexible, as anyone with a bit of talent could figure out a way to tailor it to themselves. If that weren't the case, Sun Breathing, as the original breathing style, wouldn't have given rise to so many different breathing styles.
Lizbeth, however, didn't need to develop her own breathing style since her compatibility with Love Breathing was already high enough, and on top of that, she had the even more unique swordsmanship, the War King Sword Style.
Considering this, studying a new breathing style or swordsmanship would be completely unnecessary.
In other words, the only thing Lizbeth needed to do was adjust the sword forms of Love Breathing so she could fully execute them with Moslow.
Riezel knew that wasn't hard—at least, not for Lizbeth, who had already become a Level 5 Sword Master at just fifteen.
In the end, after giving Lizbeth a few tips on what to watch out for, Riezel stopped his explanation.
"How's your stamina? Recovered yet?"
Hearing Riezel's question, Lizbeth suddenly realized that her stamina had actually recovered.
Needless to say, the reason her recovery speed was way faster than before was undoubtedly because of the effect of Love Breathing.
"Um, thank you, Master. I'm all good now!"
Lizbeth immediately stood up, hugging Moslow while flashing a silly smile at Riezel.
Of course, given the little princess's natural charm, even a silly smile looked stunning on her, proven by the way the nearby knights, who had been sneaking glances at her, suddenly turned red in the face.
Right at that moment, Raven arrived in front of Riezel, bringing Nibald along with him.
"Once the break is over, we'll head in." Raven said just as directly as always. "But before that, can you give me a few of those Autonomous Guardian Cores?"
It was clear that Raven still planned to study the Autonomous Guardian.
In the next moment, Nibald also spoke up.
"Sir Raven has already commissioned me to analyze and research those cores. If we can use modern magic technology to figure out their composition, we might be able to replicate them." Nibald said with a smile. "Personally, I'm also interested in this, so, Sir Brynhart, could you spare a few for me?"
"Don't worry, I'll pay for them." Raven added seriously. "Since there are plenty of crystals, you wouldn't mind selling us a few, right?"
Since it had been agreed beforehand that if Riezel had any magic items he didn't need, the Mavros family could buy them, Raven was being this straightforward.
Riezel glanced at Raven and Nibald before retrieving a few Autonomous Guardian Cores from the storage space of the Dimensional Magic Cube and tossing them to the two.
"Be careful, these things have self-regulating abilities—if you don't hold on tight, they'll escape."
As Riezel spoke, Raven and Nibald each caught a crystal—one immediately tightened his grip, while the other quickly pulled out a strangely shaped cloth pouch and secured the crystal inside, preventing it from slipping away.
"Much appreciated."
Raven left behind only these words before heading off to deal with the crystal.
Nibald, on the other hand, started chatting with Riezel, naturally centering the conversation around Riezel's magical expertise and Lizbeth's strength.
As a magician, Nibald was undoubtedly intrigued by how Riezel had instantly cast dozens of support magic spells on Lizbeth—his curiosity was at its peak as he bombarded Riezel with all sorts of questions, occasionally slipping in some praise for Lizbeth's performance, which made the little princess flustered.
Unfortunately, Riezel didn't give Nibald a direct answer and simply brushed it off with, "It's a special technique that only those with Imaginary compatibility can use," leaving Nibald feeling a bit disappointed.
Meanwhile, the knights were either resting, tending to their injuries, or hastily eating emergency rations to regain their strength as quickly as possible.
Ten minutes later, everyone finally stood up, preparing to continue advancing.
"Let's go. We're heading in." Raven declared flatly.
It was just a short command, yet it was enough to ignite everyone's fighting spirit.
It couldn't be helped.
One should know that this ancient city was not only ancient ruins that had never been explored before, but the entrance to this city was also wide open right before them!
Raven took the lead without hesitation, stepping into the ancient city with the three Mavros brothers following close behind.
Behind them, the knights followed suit, entering in an orderly manner.
Riezel, Lizbeth, and Nibald, on the other hand, walked side by side, bringing up the rear.
"Hmm?" Riezel suddenly stopped in his tracks.
"What's wrong, Sir Brynhart?" Nibald asked in confusion.
"Master?" Lizbeth looked at Riezel with a confused expression.
"No... it's nothing." Riezel shook his head, his expression returning to normal.
Only then did the three of them step into the ancient city, disappearing from sight.
No one noticed that after they had all entered the city, a shadowy figure suddenly appeared in the ruined area, staring at the group for a moment before vanishing without a trace, as if they had never been there.
===
Inside the Ancient City, Urban District.
As everyone arrived at this area, the place was even more ruined than they expected.
Buildings lay in shambles, resembling a wasteland, while the streets were covered in dust, uneven and full of potholes—truly a miserable sight.
Scattered along the roadside were all kinds of broken porcelain and some rusted iron tools—aside from the lack of overgrown weeds, this place was no different from an abandoned, dead city.
Riezel and the others walked along a crumbling road, keeping their movements as quiet as possible, with the only sounds echoing through the empty streets being the scraping of armor and the occasional footsteps.
No choice.
Considering this ancient city still had Autonomous Guardians roaming within it since not all of them had rushed out when they heard the commotion at the city entrance, some of them, especially those farther from the entrance, remained wandering within the city if they hadn't noticed any disturbances.
Consequently, to avoid provoking those troublesome Autonomous Guardians and triggering another battle, everyone did their best to suppress any noise.
Until—
"Look, the temple's up ahead."
Diego was the first to point forward, making everyone lift their heads.
Over there, in their sight, stood a grand and majestic structure.