Introduce a Sword Instructor?

Yukino Yukinoshita left with Asuna Yuuki, who remained silent.

As Leo watched them go, he knew Asuna might still be feeling lost and unsure what to do next. That was probably why she hadn't strongly resisted his arrangements.

"Looks like I'll have to put some effort into helping her through this."

Leo thought it wouldn't be good to leave her alone with her feelings.

Although Asuna had accepted her current situation, she was ultimately different from Yukino. There was no guarantee she could convince herself as quickly as Yukino had and adapt to her identity as a Devil.

Yukino was aloof and kept people at arm's length, but she had always had clear goals and acted decisively. She hated dragging her feet and dithering, so even if no one stepped in, she would push herself forward. She didn't need anyone to give her a nudge.

Asuna was different. She had grown up under the control of her overbearing mother and had always followed other people's plans for her life. Now that she had suddenly left the path she'd been on, if no one gave her a push, she might end up imprisoned in a cage of her own making, unable to break free.

Leo had recently looked into it. This world had neither full-dive virtual reality technology nor a quantum physicist and genius game designer named Akihiko Kayaba. So Asuna wouldn't be trapped in a Death Game, where she might undergo a profound transformation.

Without the threat of death, whether the girl would become the Lightning Flash Asuna whose name had once been renowned among the general public in his previous life was anyone's guess.

Leo quietly made a note to himself, then opened a communication magic circle in his hand and contacted Sona Shitori.

"Good morning, Leo."

A small projection of Sona soon appeared in the magic circle, and her cool voice rang out clearly.

"Good morning, Sona." Leo held up the magic circle and smiled. "I'm not interrupting anything, am I?"

"Of course not. It's the weekend, and we're not in class. You can contact me anytime." Sona smiled faintly. "So? You completed the mission, right?"

"I did." Leo shrugged. "But something came up, and I might need your help."

With that, Leo told Sona everything about last night's battle against the Stray Devil.

Sona wasn't surprised to hear that Leo had successfully defeated the Stray Devil.

She had been the one to pass the mission on to him, and she knew the details about the Stray Devil. Before betraying its master, it had been no more than a Low-Class Devil. Now, it was at most as strong as a Middle-Class Devil, so it stood no chance against Leo.

Sona had never worried that anything would happen to Leo during the mission.

But when Leo told her he had found a victim and reincarnated her as one of his servants, she was taken aback.

"'Sword Birth'?" Sona asked, clearly surprised. "Your new servant is the wielder of that kind of Sacred Gear?"

"That's right." Leo smiled. "You could call it a pleasant surprise."

"It certainly is. A servant Devil wielding a Sacred Gear that can create holy swords—if the Church hears about it, they'll probably be at a loss for words." Sona pushed up her glasses. "And Rias might have a reaction, too, if she finds out that one of your servants has this Sacred Gear."

"Oh?" Leo blinked. "What do you mean?"

"She has a servant who, like your new one, holds the Knight position," Sona explained. "That servant also wields a Sacred Gear, one that's the complete opposite of your servant's: 'Sword Birth,' which creates demonic swords."

As the name suggested, Sword Birth was a Sacred Gear that could create demonic swords.

Demonic swords were the complete opposite of holy swords—weapons imbued with demonic power and curses.

Like holy swords, demonic swords had appeared in all kinds of legends.

Gram, Balmung, Notung, Tyrfing, Dainsleif... These famous weapons were all demonic swords. Each was immensely powerful and had special abilities. Unlike holy swords, they weren't picky about who wielded them, and people capable of using them didn't come along only once every few decades. But anyone who wielded one would suffer from its curse. Without a way to resist it, they would eventually lose their lives.

Sword Birth was a Sacred Gear used to create weapons like those. It was the same type of power as Holy Sword Birth, but its exact opposite.

Holy Sword Birth was a Sacred Gear with holy attributes, while Sword Birth had demonic attributes. They weren't destined to fight to the death whenever they both appeared, the way the Red Dragon Emperor and White Dragon Emperor did in legend, but they could still be considered natural rivals in terms of their powers.

Especially Rias Gremory's Knight. If Leo remembered correctly, that servant had a deep connection to holy swords, considered them enemies, and wanted to destroy them.

If he met Asuna, he might end up hating her by association.

"Then I'll have to make sure Asuna grows quickly, so she doesn't get pushed around by a fellow servant Devil."

Leo joked with Sona.

"Nothing like that will happen. Rias will handle things." Sona let out a quiet laugh, then continued, "I understand why you contacted me. You want to train your Knight properly, so you need information about swordsmanship and sword techniques, right?"

"I don't have much choice. The Eligos Clan is old-fashioned. I couldn't find anything about that in the family library. Or maybe they had something, but it wasn't among the books they sent back to me." Leo gave a helpless shrug. "I can only ask you for help."

"That's a small matter. As long as you're not asking for the Sitri Clan's secret arts, I can decide on my own to provide you with the relevant knowledge." Sona paused. "But are you sure that's all you need?"

"What else?" Leo asked, slightly taken aback. "Do you have a better idea?"

"...More or less." Sona hesitated—unusually for her—then sighed. "If you need one, I can introduce you to a Sword Instructor."

That immediately caught Leo's interest.

What kind of Sword Instructor was she talking about?

Sona knew someone like that?

Then why did she sound so hesitant when she brought it up?

"If you're going out of your way to mention this person, this Sword Instructor must be something special, right?"

Leo rubbed his chin as he spoke.

Sona dispelled all his doubts with a single sentence.

"She's my sister's Knight."

Sona's casual remark left Leo stunned.

Sona's sister... the current Demon King, Leviathan?

A Demon King's servant? And a Knight, just like Asuna...?

Yikes...

"Um... is that really okay?"

Leo couldn't help being tempted.

That was a Demon King's servant!

A servant of the current Demon King Leviathan had to be at least an Ultimate-Class Devil, right?

Was Sona really going that far? She was arranging for an Ultimate-Class Devil to teach her servant?

"It should be fine." Sona sounded a little uneasy. "If I ask my sister, she probably won't refuse."

Of course. She was a Sister Complex Demon King. How could she refuse her adorable little sister?

Still, Sona would probably have to put up with her sister's attentions for a while. She was the one most embarrassed and bothered by her sister's doting.

And now she was willing to make such a sacrifice for her servant... Honestly, it brought a tear to his eye.

But...

"Your sister won't resent me for making you ask her, will she?"

Leo grew wary.

Everyone knew that people with a Sister Complex were unreasonable creatures. If there was even a chance that someone of the opposite sex might steal their sister away, they'd stop at nothing to get rid of him.

Even though Sona would only be speaking up for him and asking her sister to lend one of her servants as a teacher, her sister might still irrationally come to resent him.

Leo had suffered from this sort of thing before. When Sona first came to the Human World as his supervisor, she unexpectedly became close to him, and her sister had secretly tried to make trouble for him.

Sona, overcome with embarrassment, had angrily scolded her sister over and over afterward, leaving her so dejected she couldn't eat for three days. But over the past three years, Leo had still occasionally heard that her sister had kept a close eye on him.

If he ever made a move on her sister...

Leo shuddered.

"Don't worry. Supporting you is one of my duties in the Human World. Especially after I submitted your report last time, my superiors instructed me to do my best to meet your needs and ensure that nothing hindered your growth."

Sona reassured Leo, though she still didn't sound entirely certain.

"My sister... surely wouldn't openly defy the Underworld leadership's policy over such a small matter, would she?"

...Maybe. But she'd sound more convincing if she said that with a little more confidence.

Well, he'd just have to consider it a necessary price to pay for his servant's future.

So what if she was a Demon King? Once he developed the Balance Breaker for Zenith Tempest, he might be able to face one head-on.

"Then I'll leave it to you."

Leo entrusted the matter to Sona and made his decision.

"No problem. I'll let you know."

Sona was taking the plunge. She didn't want to deal with her embarrassing sister, but for her friend... she'd do it!