As time passed, the apocalyptic scene in the basement grew ever more intense. The barrier separating the inner world from the outer one began to tremble precariously, as though it might collapse at any moment.
The power Leo unleashed was gradually exceeding the barrier's limits.
Yet Leo's expression grew more and more solemn as he continued releasing that power. His gaze on Miyamoto Musashi below had changed, too.
At first glance, the entire battlefield seemed to have become his domain, filled with the power he unleashed and transformed into one natural disaster after another. But these calamities, each capable of wreaking terrifying destruction on the outside world, couldn't hurt the Flower of Tengen blossoming in the middle of the battlefield in the slightest.
The swordswoman named Miyamoto Musashi simply swung her blades freely amid the disasters, giving herself over to her swordsmanship. The calamities that kept rushing at her were split apart time and again by her seemingly unremarkable pair of swords. Not one managed to touch her.
Surging flames were cleaved in two...
Raging torrents were cleaved in two...
Lightning crashing down from the sky was cleaved in two...
Howling winds powerful enough to blow away anything in their path were cleaved in two...
Even the sand and soil heaving up from the ground and the glaciers attacking from every direction were cut apart by Miyamoto Musashi, one strike after another. None escaped her blade.
Her opponent was only a seemingly delicate swordswoman, while hers was nature itself, transformed into natural disasters. Anyone would have thought this an uneven battle that proved human strength had its limits, and that mankind could never challenge nature. Yet the swordswoman had completely overturned that assumption with the sword in her hand, showing everyone that humanity could overcome nature and conquer calamities.
Before long, the flashes of her blade began to outshine the scenes of disaster, as if they could cut even the apocalypse in two. The sight was terrifying.
"As expected, no matter how unreliable a person might seem, they can't be weak if they've become a Maou's servant."
Leo had all but confirmed that Miyamoto Musashi was among the strongest Ultimate-Class Devils. She was a genuine Ten-Winged Devil, Ten-Winged Angel, or Ten-Winged Fallen Angel in terms of combat power!
The Ten-Winged Devils, Ten-Winged Angels, and Ten-Winged Fallen Angels were all officer-level figures among the Three Factions, the high-end combat forces of their respective factions!
What's more, Miyamoto Musashi was likely at the very top even among them, an existence only one step away from Maou-Class!
He might not be her match at all!
As he realized this, Leo let out a heavy breath.
"One last strike—"
Leo's voice rang across the battlefield.
"My next attack will be the strongest one I can unleash right now!"
If this attack couldn't win him the fight, then for Leo, it would be no different from defeat.
"Here I come!"
Before Miyamoto Musashi could respond, Leo drew upon every last bit of his Demonic Power and poured it into his next attack, making the power of Zenith Tempest erupt in an instant.
The clouds overhead pressed slowly downward as countless bolts of lightning flared within them. Along with flames converging from every direction, they gathered around Leo.
The ground heaved, and the air hummed incessantly as all kinds of abnormal natural phenomena appeared one after another.
Thunderstorms, tempests, floods, sandstorms, blizzards, and fiery meteors raining from the sky... Every kind of extreme weather appeared in the basement, then transformed under Leo's control into terrifying, misshapen beasts.
The fiery meteors became a blazing Phoenix, crying out as it descended from the sky. The flood became a gigantic Water Dragon, roaring as it surged forward. The tempests, thunderstorms, sandstorms, and blizzards each became ferocious beasts that howled wildly, shaking the entire mansion.
The nightmarish sight left Asuna Yuuki stunned. Miyamoto Musashi narrowed her eyes and smiled.
"In that case, I'll bring out my strongest strike, too!"
The astonishing aura that had been gathering around Miyamoto Musashi from the very beginning erupted.
She slowly raised her swords, releasing a terrible pressure. Behind her, a massive Statue of Nio appeared, towering above them with a thunderous roar.
It was an apparition formed from pure sword pressure.
After Miyamoto Musashi had made her name in history, she chose to devote herself to Tenman Daijizai Tenjin. The Statue of Nio could therefore be considered her guardian deity, a symbol that had naturally taken shape once her Kendo reached its ultimate destination.
"One Blade Three Bows—break through Infinity and reach zero—"
Incredible Demonic Power gathered around the sword Miyamoto Musashi had raised, transforming its blade into a beam of light that extended without end.
"This strike is my Void Way, my entire life!"
Miyamoto Musashi's declaration easily drowned out the roars of the disaster beasts around Leo, ringing across the battlefield.
"Sword Roar Draw—go!"
As the words left her mouth, Miyamoto Musashi swung down her sword. The Statue of Nio behind her brought its blade down as well, slashing toward Leo.
It was a strike that seemed capable of cleaving the world apart and reducing everything in existence to zero.
As the strike fell, both Leo and Asuna Yuuki could see only a beam of light dividing the world in two, causing its two halves to slip out of alignment.
The disaster beasts charging out from around Leo abruptly collided with that boundary between worlds. Without making a sound, they split apart along with the shifting world and vanished without a trace.
"..."
Time seemed to stop in that instant. The rumbles and crashes that had echoed throughout the basement fell utterly silent.
Leo was still in the sky, and Miyamoto Musashi was still on the ground—one with his wings spread wide, the other standing with her swords raised. They faced each other in silence, one expressionless, the other still smiling.
Leo lifted his gaze from Miyamoto Musashi and looked around the basement.
The place had been battered by one disaster after another, and now a bottomless, abyss-like chasm cut through its center, splitting the entire basement almost in two.
The barrier surrounding the basement had vanished without a sound, as if it had been cleaved in two long ago. It hadn't even made a noise.
"...All right."
Leo gave a wry smile, folded away the wings on his back, and landed on the ground.
"I lose."
As soon as he conceded, time seemed to start flowing again, and the tension filling the basement dissipated.
"You fought well, Young Master Leo."
Miyamoto Musashi sheathed her two swords and walked toward Leo, looking thoroughly refreshed.
"My, it's been so long since I had a fight this satisfying. I knew I wasn't wrong about you, Young Master. You really are a worthy opponent."
The Martial Artist Miyamoto Musashi seemed completely satisfied.
"You were both amazing!" Asuna Yuuki belatedly came closer, speaking with rare excitement. "So Devils can really be this powerful? That was incredible!"
Asuna Yuuki wasn't someone who worshipped strength, but after seeing Leo and Miyamoto Musashi in action, she couldn't suppress her excitement. She even wondered whether some unknown violent streak lay hidden deep in her heart.
In truth, it was only human nature.
People couldn't help feeling excited when they saw towering mountains or felt their hearts stirred by the boundless ocean. Asuna Yuuki's feelings at that moment were much the same.
After all, until now, she had been an ordinary human. She had lost consciousness after being attacked by a Stray Devil, then woken up to learn she had become a Devil. But she hadn't really seen a Devil's power before, so this was the first time Asuna Yuuki had witnessed a supernatural battle like that. It was only natural for her emotions to run high.
"This is nothing. If you work hard, you might be able to reach this level one day."
Miyamoto Musashi smiled as she encouraged Asuna Yuuki. Her tone made it clear she wasn't just being polite.
At least, in Miyamoto Musashi's eyes, Asuna Yuuki had the potential to reach her level.
Whether she could fulfill that potential would depend on Asuna Yuuki's own effort.
"And Young Master Leo will probably surpass me with ease one day, won't he?" Miyamoto Musashi looked at Leo with shining eyes and said sincerely, "I never expected the legendary Zenith Tempest to be in your possession, Young Master. If Lady Serafall... my master, learns of this, she'll surely be astonished."
It wasn't just Miyamoto Musashi's master. If the Devils of the Underworld learned of this, it would cause a tremendous stir.
The world's second-strongest Longinus had appeared in the hands of an heir to the Eligos Clan, a family thought to have died out. If word got out, the upper echelons of the Three Factions would surely be alarmed.
To put it bluntly, with this Longinus, Leo already had the power to influence the balance of power among the various factions.
If his secret were exposed, any of the factions might take action—including the Devils.
"For now, please keep this between us," Leo said to Miyamoto Musashi. "I don't want it getting out yet."
"Of course, of course. I'll keep this secret," Miyamoto Musashi readily agreed. "As long as I'm still enjoying your hospitality here, I won't reveal it of my own accord."
In other words, once she left the mansion and finished her task, she probably wouldn't be able to keep Leo's secret when she returned to the Underworld.
After all, she couldn't go back without telling her master what had happened during her visit, could she?
So Miyamoto Musashi could only keep Leo's secret until then.
"That's enough."
Leo hadn't planned to hide it forever. He simply wanted as much time as possible to grow stronger, so he could have more control when the truth eventually came out.
With that in mind, Leo asked Miyamoto Musashi a question.
"In your eyes, how strong am I right now?"
Before you continue