Ten days had passed.
Within that time, Asta absorbed nearly everything Gabriel taught him—through nothing more than brief explanations and short bouts of practice.
His speed of adaptation far exceeded expectations, to the point that Gabriel was genuinely satisfied and ultimately declared the boy to have passed.
As a graduation gift, Gabriel created a Nichirin katana forged from Dark Matter—a blade capable of adapting to Anti-Magic.
But that wasn't all.
Gabriel also granted Asta full access to every training facility within the mansion deep in the forest, including various physical training tools and two manual books containing detailed explanations of Wind Breathing and Fire Breathing.
He did not teach those two Breathing Styles directly. Gabriel deliberately chose to let Asta walk that path on his own.
Now, Gabriel lounged back in a reclining chair at his base.
Around him, the results of his explorations were neatly arranged: Dark Matter creations, piles of gold, Magic Tools, and other valuable artifacts taken from dungeons.
He had gathered all of it at night, in the gaps between training Asta. But now—there were no experiments. No training.
Gabriel's gaze rested on the ceiling of the base. In his mind, a single question echoed quietly:
"What kind of cool thing should Ash do next?"
"I still have two months and ten days left in this world," Gabriel murmured softly, then glanced toward Beatle as it hovered calmly nearby.
The pale white stag beetle carried within it all the knowledge he had stolen—Loropechka's memories, Lucius Zogratis and Forbidden Magic, and countless fragments of crucial information about this world's magic system.
"Experiments can be done anytime," he continued quietly. "So… what's the next move?"
For a brief moment, an idea surfaced—attacking one of the Dark Triad.
Not because of a mission. Not out of necessity. Simply because… it would look cool.
But the observer's instinct within Gabriel immediately restrained that impulse. He knew the Dark Triad were overwhelmingly powerful.
As an Observer, he would first master Total Concentration Breathing to strengthen himself further, and only then construct a plan with cold, precise calculation.
"Heh… decision made," Gabriel muttered, a faint smile forming on his lips.
"My next target as Ash—"
His gaze hardened, calm yet filled with unwavering conviction.
"The Bearer of Demon Power."
***
Meanwhile, upon a vast expanse of grassland stretching as far as the eye could see, a lake thirty kilometers in diameter rippled under the force of the wind, while the grass danced lightly across the earth.
In the air hovered a handsome young man with messy black hair, dressed in long black attire, his body wrapped in flowing wind.
It was Yuno, a gentle smile resting on his face. Beside him floated a fairy in a green dress, her expression perpetually sulky.
The fairy was Sylph, the Wind Spirit—often called Bell. She looked visibly irritated, because Yuno's smile was directed not at her, but at someone else: a short yet powerfully built youth standing on the grass below, his presence sharp and resolute.
That youth was Asta. He had removed his weighted bracelets, and his right hand firmly gripped the Demon Slayer Sword, its blade leveled toward Yuno.
"Well?" Asta said enthusiastically. "Surprised, aren't you, Yuno?!"
"If you want to surprise me…" Yuno replied calmly, "you'll have to do more than that, Asta."
Asta grinned, resting the Demon Slayer Sword casually on his shoulder.
"Tch… you sure talk big," Asta shot back with fiery enthusiasm. "Just wait until I really get serious!"
The faint smile on Yuno's face slowly faded.
The wind around them suddenly stopped—as if the world itself were holding its breath. That brief silence felt heavy, pressing down on the air between the two of them.
For a moment, Yuno glanced to the side.
"Bell," he said curtly.
Bell jolted, her eyes widening slightly. "Hah!? Seriously? You're using Spirit Dive just to fight this shorty?" She pointed at Asta with an incredulous expression. "What's so special about that short kid anyway?!"
Despite Bell's nonstop complaints, Yuno didn't react at all.
To him, Bell's grumbling was nothing more than a passing breeze—and that indifference only made her even more irritated.
"Hmph… fine! If that's what you want, Yuno!"
The wind around them began to swirl slowly, growing denser and heavier by the second. The grass beneath their feet rustled, then was pressed flat against the ground.
Bell's body shone with a vivid green light, then dissolved into countless particles of wind, spinning rapidly as they enveloped Yuno from every direction. The whistling of the wind rose sharply, piercing the ears.
That light was completely absorbed into Yuno's body.
In an instant, the wind that had once felt gentle turned sharp and savage. The surface of the distant lake rippled violently, as if responding to the sudden, unnatural surge of mana.
Along one side of Yuno's body, green mana wrapped around him and his clothing. A crown and bracelets formed from pure mana, emitting a faint yet elegant glow.
Spirit Dive—complete.
Yuno looked at Asta once more. This time, there was no smile. No excess emotion.
"Now," he said flatly, his voice nearly swallowed by the roaring wind, "don't blink, Asta!"
"Tch… you bastard," Asta replied with a defiant grin, his voice trembling with adrenaline. "So you're finally getting serious, huh? Then—so will I…!!!"
Asta leveled the Demon Slayer Sword straight ahead. His right hand clenched the hilt tightly, while his left hand rested against the jet-black blade, which throbbed faintly.
He closed his eyes.
Inside his body, Anti-Magic surged—wild, rough, yet overwhelmingly familiar. The next instant, Asta's eyes snapped open. His right eye now burned crimson, sharp like a living ember.
Anti-Magic erupted and exploded outward. Flashes of dark red lightning tore through the air, and the atmosphere instantly grew heavy and oppressive.
The ground beneath Asta's feet cracked, and the sheer pressure was enough to make the corner of Yuno's lips lift slightly—in a grin.
Half of Asta's body turned black. A horn emerged from the side of his head, and black wings spread wide from his back, ripping through the air around him.
Seeing that transformation, Yuno raised his left palm, aiming it straight at Asta.
"Spirit Magic: Spirit Storm."
A blast of wind shot forth instantly—like a green laser compressed to its absolute limit. It roared as it spun, carrying a shredding force capable of pulverizing diamond in an instant.
"Mizu no Kokyū," Asta said as he drew in a deep breath.
With total focus, he leveled the tip of the Demon Slayer Sword straight ahead, then thrust it directly into the core of Yuno's Spirit Storm.
"Seventh Form: Drop Ripple Thrust."
A single thrust.
In an instant, the Spirit Storm shattered into pieces—the green wind unraveling and dispersing, leaving behind torn earth and shredded air in its wake.
The remaining Anti-Magic spread outward slowly, forming gentle ripples—like droplets touching the surface of a calm pond.
For a brief moment, time itself seemed to slow.
Asta drew in another long breath through his nose. His lungs expanded to their limit, blood flow accelerating as heat surged sharply through his body.
At the same time, he exhaled through his mouth.
"Black Meteorite."
In the very next instant, Asta vanished from where he stood—shooting straight toward Yuno, leaving a trail of destruction carved through the air behind him.
The moment he appeared right in front of Yuno, Asta swung the Demon Slayer Sword in a brutal vertical slash, Anti-Magic rippling violently along its blade.
But—Yuno evaded it effortlessly.
His body slid sideways on a gust of wind, a faint smile on his lips as he maintained perfect distance. In the blink of an eye, Yuno was already soaring away, leaving Asta behind.
As fast as a raging storm, the gap between them exploded open—twenty kilometers crossed in a single second.
High in the sky, Yuno raised his left hand. The surrounding wind converged at once, spiraling and compressing into a brilliant green vortex that crushed the very air.
At the same time, the pages of Yuno's grimoire fluttered wildly, flipping again and again—until they suddenly stopped.
"Wind Spirit Creation Magic: Spirit of Zephyr."
A burst of green light erupted.
A long sword formed from pure wind mana—sleek and razor-sharp, its translucent blade humming as if it were alive. Yuno gripped it firmly, the aura of Spirit Dive flowing seamlessly into the weapon.
It wasn't over yet.
The pages of the grimoire began to flip again—once, twice, three times—until they changed eleven times before locking in place.
"Mana Zone."
In an instant, the surrounding mana bowed under Yuno's dominion.
"Wind Magic: Crescent Kamaitachi."
With a single swing of the Zephyr sword, Yuno unleashed the attack.
Ten gigantic wind crescents shot forward in succession, carving through the sky with blazing green arcs.
Each blade of wind spun violently, directly reinforced by the power of the Wind Spirit—sharp enough to tear mountains apart, dense enough to slice through the very airspace itself.
On the other side, Asta clicked his tongue softly.
"Tch… Demon-Dweller Sword."
He drew the Demon-Dweller Sword from his grimoire. Anti-Magic immediately surged forth, wrapping the blade in a thick, pitch-black aura.
__
Author's note:
Hey, how's it going? Do you like it? Add it to your favorites, give it a good review, and leave a comment. 😉
There are almost never duels in anime, so I made this one every now and then.
Ehehehe... how is it? Do you like it? Type it in the comments. 😄