Yukinoshita Yukino left with the silent Yuuki Asuna.
Leo, who watched the two depart, knew that Yuuki Asuna might still be somewhat lost and unsure of what to do next, which was why she hadn't particularly resisted his arrangements.
"It seems I'll need to put in some effort to guide her."
Leo felt that leaving her alone might not be a good thing.
Although she could accept the current situation, Yuuki Asuna and Yukinoshita Yukino were ultimately different. Yuuki Asuna might not be able to convince herself and adapt to her Demon identity as quickly as Yukinoshita Yukino had.
Yukinoshita Yukino was reclusive and aloof, but she had always had clear goals, and her style of action tended to be decisive, disliking procrastination and hesitation. Therefore, even if left alone, she would push herself forward and didn't need anyone to actively motivate her.
Yuuki Asuna was different. She had lived under the control of her strong mother since childhood, always following others' arrangements. Now, suddenly detached from her original life path, if no one pushed her, she might very well be trapped in a cage of her own making, unable to break free.
Leo had also checked not long ago; this world had neither full-dive virtual reality technology nor a quantum physicist and genius game designer named Kayaba Akihiko. Therefore, Yuuki Asuna would not be trapped in a death game and undergo a spiritual transformation there.
Without the threat of death, whether this young girl would transform into the 'Lightning Flash Asuna,' renowned among the general public in his past life, was truly an unknown.
Leo secretly made a note of this matter, then activated a Magic Circle for communication on his hand and contacted Sona Sitri.
"Good morning, Leo."
Sona Sitri's small projection quickly appeared on the Magic Circle, her clear, cool voice resonating distinctly.
"Good morning, Sona." Leo held up the Magic Circle and smiled, "I hope I'm not disturbing you?"
"Of course not. Today is the weekend, and it's not class time. You can contact me anytime." Sona Sitri returned a faint smile and said, "How was it? Was the subjugation mission completed?"
"It was completed." Leo shrugged and said, "But I have something here that might require your help."
With that, Leo recounted the entire process of subjugating the Rogue Demon last night to Sona Sitri.
Sona Sitri was not surprised to learn that Leo had successfully subjugated the Rogue Demon.
It was a mission she had handed over to Leo, and she had information about that Rogue Demon. She knew that before betraying his master, the Rogue Demon was merely a low-ranking Demon, and now, at most, possessed the strength of a Mid-level Demon. He couldn't possibly be Leo's opponent.
Therefore, Sona Sitri was not at all worried that Leo would encounter any problems with this mission.
However, when Leo said he had encountered a victim and reincarnated her as his Retainer, she was surprised.
"'Holy Sword Creation'?" Sona Sitri said, very surprised, "Your newly acquired Retainer is actually the wielder of such a Divine Artifact?"
"Yes." Leo smiled, "This can be considered a pleasant surprise."
"It certainly is a pleasant surprise. A Familiar Demon actually possesses a Divine Artifact capable of creating Holy Swords. If the Church gets wind of this, they'll likely be exasperated, won't they?" Sona Sitri pushed up her glasses and said, "And Rias, if she knew one of your Retainers held this Divine Artifact, she would probably react."
"Oh?" Leo blinked, "And why is that?"
"She has a Retainer under her command, just like your new one, both are of the 'Knight' rank." Sona Sitri explained, "That Retainer is also a wielder of a Divine Artifact, and the Divine Artifact she holds is a completely opposite but similar type to your Retainer's—'Magic Sword Creation (Sword Birth)'."
Magic Sword Creation, as the name suggests, is a Divine Artifact capable of creating Magic Swords.
Magic Swords are the complete opposite of Holy Swords, weapons filled with demonic energy and curses.
Like Holy Swords, Magic Swords have also appeared in various legends.
Gram, Balmung, Notung, Tyrfing, Dáinsleif... these famous weapons are all Magic Swords, each immensely powerful and possessing special abilities. They are not as picky about their users as Holy Swords, not requiring decades for someone to appear who can wield them, but those who use them will be afflicted by the sword's curse. If they don't have a way to resist the curse, they will eventually lose their lives.
Magic Sword Creation is a Divine Artifact used to create such weapons, a power of the same type but completely opposite to Holy Sword Creation.
Holy Sword Creation is a Holy-attribute Divine Artifact, and Magic Sword Creation is a Demonic-attribute Divine Artifact. While the two might not always fight to the death like the legendary Red Dragon Emperor and White Dragon Emperor every time they appear together, from a fundamental nature, they can certainly be considered natural rivals.
Especially Rias Gremory's 'Knight,' if Leo remembered correctly, she seemed to be someone with an intricate connection to Holy Swords, viewing them as enemies and wishing to destroy them.
If she were to encounter Yuuki Asuna, she might harbor animosity towards Yuuki Asuna out of association, wouldn't she?
"Then I'll have to diligently urge Asuna to quickly grow stronger, so she isn't bullied by peer Familiar Demons."
Leo joked with Sona Sitri.
"It won't come to that; Rias will handle such matters." Sona Sitri chuckled, then said, "I understand your intention. You want to properly cultivate your 'Knight,' so you're looking for knowledge related to swordsmanship and sword techniques, right?"
"I can't help it; the Erigor Family is old-fashioned. There's basically no such knowledge in the family's library, or perhaps there was, but it wasn't included in what was returned to me?" Leo said helplessly, "I can only ask you for help."
"That's a small matter. As long as you're not asking for the Sitri Family's generational secrets, I can make the decision myself and provide you with relevant knowledge." Sona Sitri said, "However, are you sure that just having relevant knowledge is enough?"
"Otherwise?" Leo paused slightly and said, "Do you have a better method?"
..."Almost." Sona Sitri hesitated for a rare moment, then sighed and said, "If you need it, I can introduce you to a swordsmanship teacher."
These words immediately piqued Leo's interest.
What kind of swordsmanship teacher?
Sona Sitri knew such a person?
Then why did she react this way when bringing it up?
"To be specifically mentioned by you, this so-called swordsmanship teacher must be extraordinary, right?"
Leo stroked his chin and spoke thus.
Then, Sona Sitri dispelled all of Leo's doubts with a single sentence.
"That's my sister's 'Knight'."
Sona Sitri's light remark instantly stunned Leo.
Sona Sitri's sister... the current Demon Lord Leviathan?
A Retainer of a Demon Lord? And a 'Knight' just like Yuuki Asuna...?
Hiss... "This... is that really okay?"
Leo was disgracefully tempted.
That was a Retainer of a Demon Lord!
A Retainer of the current Demon Lord Leviathan, that would at least be a Highest-level Demon, right?
Is Sona Sitri being so generous? Directly finding a Highest-level Demon to be a teacher for his Retainer?
"It should be fine." Sona Sitri said somewhat unnaturally, "As long as I ask my sister, she shouldn't refuse."
Of course, after all, she's a sister-complex Demon Lord, how could she refuse her cute sister's request?
It's just that Sona Sitri will probably be bothered by her sister for a while. She's the one who feels the most ashamed and repulsed by her sister's doting and spoiling.
Now, she's willing to make such a big sacrifice for her own Retainer... She truly is, I'm moved to tears.
However... "Your sister won't develop hostility towards me just because you specifically requested her for my sake, will she?"
Leo became a little wary.
It is well known that sister-complexes are unreasonable beings. Once their sister has any possibility of being taken away by an outsider, these unreasonable beings will stop at nothing to eliminate the threat.
Even if Sona Sitri merely spoke up for him, asking her sister to lend a Retainer as a teacher, the other party might unreasonably resent him.
Leo was not without experience in this regard. When Sona Sitri first came to the human world, became his supervisor, and unexpectedly developed a good relationship with him, that person had secretly caused him trouble.
Although afterward, the other party was angrily lectured by an extremely embarrassed Sona Sitri again and again, so much so that he couldn't eat for three days, Leo still occasionally received news over these three years, knowing that the other party had been keeping a close eye on him.
Once he made a move on her sister... Leo couldn't help but shiver.
"Don't worry, supporting you is one of my missions in the human world. Especially after I submitted your report last time, I've been instructed by the higher-ups that as long as you have a need, I should try my best to fulfill it and ensure your growth is not hindered."
Sona Sitri reassured Leo, but she was still somewhat uncertain.
"My sister... she shouldn't publicly break the action guidelines set by the higher echelons of the Underworld for such a small matter, right?"
...Perhaps, but if you could sound more resolute instead of so uncertain, it would be more convincing.
Forget it, consider it a necessary price to pay for the future of his Retainer.
It's just a Demon Lord, isn't it? Once he develops the Forbidden Hand of Blazing Heaven Thunder Prison, he might not be unable to confront her head-on.
"Then I'll leave it to you."
Leo handed this matter over to Sona Sitri, making his decision.
"No problem, wait for my news."
Sona Sitri was also going all out. Although she was unwilling to deal with that embarrassing sister of hers, for the sake of her good friend... she'd risk it!