Half an hour later, in the training room beneath the estate…
A surge of red light flashed, and Leo stepped out of the magic circle, returning home.
"Finished with your business, Leo-sama?"
Miyamoto Musashi, who had been coaching Asuna, sensed the activation of the circle the moment it lit up. She waved casually as Leo emerged.
"More or less." Leo glanced at Asuna, who was still maintaining her precise sword grip with full concentration, then added, "At the very least, her family isn't against it anymore."
After whispering temptations like a devil earlier, Leo had introduced the Yukinoshita women to the benefits of becoming his servant. He'd also given them a crash course on the Underworld.
To ordinary humans, the Underworld was hell—the devils' domain—certainly not a place anyone would want to live. In legends, it was a world filled with burning crimson flames and endless torment.
But the truth was different.
That terrifying hell people imagined was actually the lower layer of the Underworld: the realm of the dead. The upper layer wasn't scary at all.
There was no sun or moon, but there was a sky—purple, instead of the refreshing blue of the human world.
There was no ocean, only vast lakes as large as continents. The population was far smaller than humanity's, even if one added up all the races living there. Land was expansive and dirt cheap—nothing like the human world where every inch cost a fortune.
There were forests filled with monsters like hydras, water spirits called undines, blue thunder dragons, and slimes. There were cities—not harsh wastelands, but beautiful places far more refined than many human cities, at least within devil territories.
As the Maou themselves said: it was the twenty-first century. Humans knew how to build comfortable cities. Devils lived longer and had supernatural power. Why wouldn't they build pleasant places to live?
If they could live comfortably, why choose to suffer?
So the Underworld wasn't the nightmare humans imagined—it was incredibly livable. Many devils dreamed of retiring to some peaceful corner to enjoy quiet days. In some ways, it was more pleasant than heaven.
While explaining all this, Leo also introduced his own domain in the Underworld: the Eligos Territory, giving the Yukinoshita women a sense of the massive estate he owned.
Because the Underworld's land was so vast, even though the Eligos family had died out, no one bothered to seize the territory—it simply lay dormant. When Leo inherited the Eligos name, the entire territory was returned to him untouched.
And the Eligos Territory was larger than an entire prefecture.
Thinking back to how their jaws dropped when he mentioned giving part of that land to Yukino as her own estate, Leo almost laughed out loud.
When they learned Yukino wouldn't become a universally hated monster, wouldn't be treated like a slave, and would instead gain longevity, eternal youth, and even the right to inherit and develop a territory—Mrs. Yukinoshita and Yukinoshita Haruno were visibly tempted. For a moment, they looked ready to abandon their human status and follow him too.
Compared to their earlier resistance, it was night and day.
In the end, there was no suspense. The Yukinoshita family accepted Yukino becoming a devil—and accepted her becoming Leo's servant.
It was a done deal anyway. Even if they wanted to oppose it, what could they possibly do?
Use the power of the Yukinoshita family? Against Leo?
Maybe they would've thought so if they hadn't witnessed Yukino's fight with Sharon. But after seeing that battle, Mrs. Yukinoshita and Haruno understood perfectly that they couldn't resist Leo at all.
Especially after Leo explained what jobs devils held in the human world—and how many major figures in Chiba Prefecture were part of his network—both women realized that even without supernatural means, he could crush the Yukinoshita family without effort.
Chiba Prefecture didn't belong solely to them. There were other, even stronger clans. Some of those clans served Leo.
What could they possibly do?
They could only accept it.
So Leo returned in triumph, leaving Yukino behind so the three women could talk privately.
Of course he allowed it—he wasn't unreasonable.
"With the private tutor settled, all that's left is the Yuuki family. That should be easy enough."
While he was at the Yukinoshita residence, he'd received word from his contacts that Asuna's parents were already on their way to Chiba Prefecture and would meet him tonight.
His contacts were preparing the venue—luxurious and imposing, naturally.
So…
"We're going to the banquet tonight. Asuna, don't train too late."
Leo warned softly.
"...Got it."
Asuna's grip tightened slightly. Her voice was quiet. Clearly, she wasn't calm.
Leo didn't care at all—it was like he was going to meet subordinates, not future in-laws.
That was the perk of not dating and only taking servants.
If it were romance, their parents would be his future father- and mother-in-law, and he'd have to show respect.
But a servant's parents? They were practically obligated to treat him like a boss.
"So, Leo-sama has no plans until tonight?" Miyamoto Musashi asked suddenly. "In that case, want to spar with me?"
Both Leo and Asuna froze.
"You're challenging me?"
Leo pointed at himself in surprise.
"Sure am." Musashi replied cheerfully. "I've heard all about it. You awakened a mutant trait—more servants means more strength, right?"
"I haven't fought anyone in ages. I'm itching for a match."
A challenge from Miyamoto Musashi wouldn't have been strange at all in her era.
As a wanderer, she lived for crossing blades with the strong.
She wasn't bloodthirsty—battle was simply the path to sharpening her sword.
For a true swordsman, not challenging a worthy opponent would be stranger.
However…
"And what makes you think I'm strong?"
Leo asked with interest.
Based on what he'd shown publicly, most would think he was just a six-winged High-Class Devil at best.
Against normal enemies, sure—he was strong.
Against Miyamoto Musashi?
Who would believe that?
Musashi might only have four wings, but she was the strongest swordsman in history, servant of Serafall Leviathan. Her true power was easily Ultimate-Class Devil tier—probably not the lowest eight-wing kind either, but a ten-wing monster.
Meaning Leo was at least one tier below her—maybe two.
One tier was already a gulf. Two tiers was an uncrossable chasm. It wouldn't even be a fight—just a beating.
Unless… Leo used his real power.
But Musashi didn't know what his real power was.
Except—
"Don't underestimate a swordsman's intuition, Leo-sama."
Musashi's eyes gleamed, bright as if she'd opened a "mind's eye" or "divine eye." A fierce smile stretched across her face.
"My blood, bones, flesh—my entire being tells me the one standing before me is worth fighting. How could someone like that not be strong?"
Leo's brows rose.
Then he smiled.
His own battle instinct stirred. His devil blood boiled, urging him to fight—to unleash chaos.
"If a Maou's servant says so, I'd be rude not to answer."
Flames lit his eyes.
"Come at me, then."
That bold response made Musashi grin wider.
...
Moments later, the room felt like the calm before a storm.
Asuna, who had been practicing her grip, had retreated fully behind the barrier at the room's edge, watching anxiously.
Leo unfurled his wings and floated into the air, taking the advantageous position.
Musashi didn't move. She remained on the ground, looking up at him with a fearless smile.
"You can start, Leo-sama."
She drew one of her paired swords, resting it casually on her shoulder.
"Then I won't hold back."
Her stance was relaxed—but her aura had already spiked dangerously. Leo didn't hesitate.
"Boom!"
A torrent of demonic power erupted from him, filling the training room with roaring pressure.
And with that—
The battle began.