As the two stronger Autonomous Guardians guarding the city entrance were taken down, the oppressive atmosphere in the air instantly lightened, making everyone subconsciously breathe a sigh of relief.
Before long, even though more Autonomous Guardians rushed out of the city one after another, compared to the two at the entrance, these ones were undoubtedly much weaker.
However, this time, it wasn't just Riezel, Lizbeth, Raven, and Nibald taking action—Kaiser and the others also stepped onto the frontlines, engaging the Autonomous Guardians in battle together.
Ordinary Autonomous Guardians had STR and END equivalent to Level 7, but their DEX and AGI were only at Level 5, so even Axel and Diego, who were only at Level 5, could fight against them and were fully capable of holding their ground on their own as long as they avoided the stone spears and fists of the Guardians.
Meanwhile, the knights of the Mavros family, who were around Level 4, were in quite a similar situation where they definitely couldn't win in a one-on-one fight, but in group combat, things were different.
Against the Autonomous Guardians, the swordsmen took the front lines as vanguards, engaging in guerrilla attacks to draw the attention of the Guardians and disrupt their attacks, while the magicians in the back focused on support—either supporting the vanguards with magic or bombarding the Guardians with offensive magic and debuffs.
With this kind of coordination, even a hundred swordsmen could hold off around ten Autonomous Guardians, stopping their charge and leaving them helpless.
As for Raven, Nibald, Lizbeth, and Kaiser, their roles were even more straightforward—acting as damage dealers.
It couldn't be helped.
Considering the Autonomous Guardians had END that ranked among the highest in Level 7, even if Axel, Diego, and the knights could restrain them, it was difficult to deal any real damage. Only a few people, including Lizbeth, had the ability to hurt the Guardians.
Lizbeth, of course, needed no explanation.
Moslow, the sword she wielded, was an extraordinary ancient mystical treasure, which, in Riezel's eyes, was even stronger than first-class special equipment in the world of Danmachi.
Moreover, Riezel had also enhanced it with magic like 'Bless Weapon' and 'Magic Weapon', so given the little princess had already succeeded in breaking through the defenses of the two stronger Autonomous Guardians guarding the city entrance earlier, these weaker ones were nothing in comparison.
Raven was the same.
Rebellion, known as the strongest offensive weapon in Jinas, was also an ancient mystical treasure, so when adding the Dark Abyss Sword Style that provided additional enhancements, it was easy to break through any defenses.
Nibald, on the other hand, relied on the power of a magic item he carried, continuously bombarding the Autonomous Guardians with high-powered elemental magic from the Transformation System—at the very least, he could peel off a layer of their tough skin.
As for Kaiser, normally, as a Level 6 Sword Master, he shouldn't have been able to break through the defenses of the Autonomous Guardians, but as Raven's eldest son and the one regarded by many as the next Guardian Sword Saint, he also carried a mystical treasure.
However, it wasn't a mystical treasure from the ancient magic civilization but a modern one born from the technological advancements of the modern magic civilization.
Even though the modern magic civilization wasn't as powerful as the ancient magic civilization, over thousands of years of development on the Akasha Continent, there were still exceptional individuals who dedicated their entire lives to crafting powerful items.
Yes, these modern mystical treasures might not be as powerful and versatile as the ancient ones, but they were undoubtedly far superior to ordinary magic weapons, magic armor, or magic items.
For example, Albert Borley, the heir of the Borley family, once considered the best swordsman just below the Sword Saint, who had fought Riezel in the royal palace where Riezel secured his position as a Sword Saint, had drawn his sword in front of Riezel, which had a glorious history within the Borley family.
It was said that even the past Borley family's Sword Saints had once wielded that sword, acknowledged as a magic weapon with immense power.
In terms of sheer sharpness, it might not have been much weaker than Raven's Rebellion, but unlike Rebellion, which had special abilities like breaking defenses, magic, and curses, Albert's sword lacked such abilities.
Nevertheless, it had its own special ability, which was nearly indestructible, having never shown any signs of wear to this day. It was believed that even a weapon like Rebellion, an ancient mystical treasure that could break any defenses, might not be able to chip it.
Such was the nature of modern mystical treasures—masterpieces of modern magic civilization, forged by legendary craftsmen over centuries.
Kaiser, as the eldest son in the Mavros family, wielded a weapon that ranked among modern mystical treasures—a masterpiece forged from the rarest metal in Jinas by a master blacksmith, working alongside three Structure System Magicians proficient in alchemy magic.
Emitting faint particles of light, while the sharpness of the sword in Kaiser's hand might not match Rebellion, it possessed a special ability that only Rebellion had—defense breaker.
As a result, working together with Raven and Nibald, Kaiser also could harm the Autonomous Guardians, inflicting wounds on their massive bodies.
Thanks to the injuries they created, Axel, Diego, and the knights were able to deal damage to the Autonomous Guardians as they targeted those injuries, tearing apart the Guardians' flesh as much as possible.
Lastly, there was Riezel.
What did he do?
He was soloing.
He seemed to be getting addicted to the feeling of everything around him being blown away in an instant when using 'Nuclear Blast', so whenever Autonomous Guardians charged out from inside the city, he would cast Greater Teleportation to appear right in the middle of their densest formation before unleashing 'Maximize Magic – Nuclear Blast' on the spot.
With its massive blast radius, Riezel really felt like he was bringing about world peace through nuclear explosions, as with just one Nuclear Blast, everything instantly went silent.
In a situation like this, even if the Autonomous Guardians had extremely high END, far beyond Level 7, they still ended up crumbling into dust within the explosion.
Normally, Nuclear Blast wouldn't be this powerful, but since half of its attribute was fire, the magic, which had fast casting speed, a huge area of effect, and inflicted all kinds of abnormal status effects, had its one major flaw, which was lack of damage, completely compensated for.
As for its other flaw, which was hitting both friend and foe, Riezel just had to make sure he avoided his allies before casting and setting up 'Body of Effulgent Beryl' as a shield.
In that way, its flaw basically didn't exist as flaws anymore.
Ultimately, the more Riezel used Nuclear Blast, the more he got hooked.
In fact, Riezel got hooked on Nuclear Blast mainly because it felt even more satisfying to use than a ranged instant-death magic like 'Cry of the Banshee'.
It was only natural.
Which men didn't like explosions?
If it weren't for the fact that there were still people of the Mavros family nearby, along with Nibald and even Lizbeth, he wouldn't just be using 'Maximize Magic - Nuclear Blast' but 'Widen Magic - Nuclear Blast' instead.
No choice.
If Riezel enhanced Nuclear Blast with Widen Magic, its attack range would absolutely be big enough to send not just the Autonomous Guardians but also Lizbeth, Nibald, and the Mavros family's people flying.
Nonetheless, this situation involuntarily gave Riezel an increasingly strong feeling.
'Maybe I'm already touching the edge of becoming a Strategic-Class Magician?'
It could be said that with Riezel's current level and MAG, his strongest magic, after being enhanced by Mage and Magic Chant, then further amplified by Pioneer of the Sun, would undoubtedly have earth-shattering power.
Super-Tier Magic like Fallen Down was a prime example.
Even before leveling up and obtaining Magic Chant, Riezel had been able to blast through the heavily fortified first three floors of the Great Tomb of Nazarick.
Now, after leveling up, gaining Magic Chant, and further improving Mage, just how much more terrifying would Fallen Down be?
And what about wide-area annihilation magic like Rea Laevateinn?
Rea Laevateinn, personally taught to him by Orario's strongest mage, had destructive power that might not be far off from a Super-Tier Magic like Fallen Down when enhanced by Pioneer of the Sun.
'Among them, the attack power, damage, and overall output strength—Fallen Down probably is the highest.'
'But in terms of attack range, Rea Laevateinn is a step above as wide-area annihilation magic.'
'Plus, while Super-Tier Magic can't be enhanced, the magic from the world of Danmachi can.'
In the past, Riezel had used 'Silent Magic - Arcs Ray' to prove that the magic from the world of Danmachi could be strengthened using Metamagic Enhancements from the world of Overlord.
Unfortunately, because of a fundamental rule in the magic system of YGGDRASIL, Super-Tier Magic couldn't be enhanced with Metamagic Enhancements, so even a max-level pure magic caster like Ainz couldn't override it.
However, the magic born from Falna in the world of Danmachi apparently didn't fall under this restriction, so if that was the case, Riezel could fully enhance wide-area annihilation magic like Fusillade Fallarica and Rea Laevateinn—expanding their effective range and increasing their power.
'Rea Laevateinn with Widen Maximize Magic, huh...?'
Riezel had a feeling that if he cast this magic, its power would definitely surpass Tactical-Class Magic by a long shot.
Would he be able to use this magic to wipe out an entire large city or even a small country?
If he could, then he would become the ninth Strategic-Class Magician on the Akasha Continent.
'Strategic-Class Magician...'
Riezel's eyes flickered as he floated in midair.
For the current him, even if he became a Strategic-Class Magician—someone so powerful that entire nations would covet him and others would see him as a weapon of war—he was sure Jinas wouldn't dare use the same restrictions on him as he did on Yuri.
Even so, he honestly wasn't particularly interested in becoming one of the highest-class magicians on the Akasha Continent.
Nonetheless, if the strongest offensive magic he could cast really reached strategic-class attack power, then he had a target to test it in mind.
With this thought, Riezel looked across the cavern chamber, then down at the earth beneath him, and finally up at the ceiling.
In the next moment, the corners of his mouth curled slightly.
'Not yet...'
Making this judgment, Riezel used teleportation magic and retrieved a few more Autonomous Guardian Cores that were about to fly away, but his actions eventually attracted quite a bit of attention.
"Sir Brynhart, the crystals that flew out from their bodies... do they have some kind of special function?"
As Riezel approached, Nibald took the chance to ask him this question while glancing at an Autonomous Guardian Core in his hand.
"Well, this thing is called an Autonomous Guardian Core, the core of these Autonomous Guardians." Riezel explained calmly, not hiding anything. "As long as you have this core, you can use certain methods, just like using Structure System Magic, to directly regenerate an Autonomous Guardian."
He explained without caring about the shock it brought to everyone.
"You mean... it can straight-up create an Autonomous Guardian?!"
After hearing this, those from the Mavros family, including Raven, couldn't help but stare at the crystal tightly gripped in Riezel's hand, their eyes filled with greed since they knew very well just how powerful an Autonomous Guardian was.
If they could take control of many such Autonomous Guardians and deploy them onto the battlefield, just how terrifying would that be?
On a chaotic battlefield, Autonomous Guardians with high attack, high defense, and insanely thick endurance would definitely be the ultimate weapons for siege warfare, right?
Having this thought, Raven and the others couldn't help but feel tempted, but just as they were getting excited, Riezel abruptly poured cold water on their hopes.
"Don't get too happy just yet."
"First off, we don't know the method to regenerate an Autonomous Guardian, just like how you gotta learn a specific Structure System Magic to create a certain object."
"Second, even if you do regenerate an Autonomous Guardian, these things will only act according to the magic program embedded in them when they were originally created. In other words, whatever purpose they were made for, that's the only thing they'll follow since they won't do anything outside of that."
"And the purpose of the Autonomous Guardians here is pretty obvious—to protect this ancient city, which was already set in the magic program when the core was created. It can't be changed or replaced, so even if you regenerate them, thinking you can use them for anything other than guarding this ancient city is impossible."
Riezel's cold dose of reality instantly extinguished the fire of greed burning in everyone's heart.
And this was without him even telling them that once an Autonomous Guardian was regenerated, getting it to move would also require a massive amount of energy that came from them consuming Demon Beast Insects, dissolving them inside their internal space, and injecting their essence into the core's radiance.
Outside of this place, which was crawling with Demon Beast Insects, where else could they find enough Demon Beast Insects to feed the Autonomous Guardians and convert them into usable energy?
"In short, they're only valuable for research purposes."
Riezel weighed the crystal in his hand and spoke casually.
"Anyway, stop wasting time thinking about this. Getting inside the city is what matters right now."
Hearing this, everyone nodded and picked up the pace, continuing their advance.