"A Sacred Gear that can kill gods and Maou… a Longinus?"
The underground training chamber had turned into a frozen wasteland. Yukino stared blankly at the ice-born creature standing behind her, her mind spinning.
She couldn't fully grasp what kind of power a Longinus held—but when she looked around at the vast chamber, large enough to fit several soccer fields, now completely covered in ice, she finally understood why the fallen angels had seen her as a threat.
If that kind of power had been unleashed in the human world, the result would have been catastrophic.
Realizing that, Yukino felt a chill of fear run through her.
"If that power had gone off back at the start of term… then my mother and Haruno…"
They would've ended up like those car tires—frozen solid.
And everyone on that street… turned into ice statues.
If someone around her possessed such destructive power without even knowing it—someone who could lose control at any time—she would have seen them as dangerous too.
She wouldn't have wished them dead, maybe, but deep down, she'd want them far away. Somewhere they could never come back from.
"Now you understand?" Leo patted her shoulder lightly. "No one wants to see that kind of power go unchecked."
"So even if you didn't want to become a devil, the angels or the fallen angels would've taken you away. Either way, you wouldn't be able to go back to your normal life."
"In a sense, me taking you in as my servant probably made a lot of people breathe easier. It means someone's here to keep an eye on you, to control you. The risk of you losing control is now next to zero."
He smiled faintly. "So? Still have complaints?"
Yukino was silent for a long moment before letting out a sigh.
"I'm… not exactly happy about it, but that doesn't mean I'm resentful." She spoke quietly but firmly. "I know that if you hadn't reincarnated me as a devil that day, I would've died."
"So no, I don't hate you. In fact… I'm a little grateful."
"I just can't get used to it yet—seeing this kind of world, becoming something that's not human…"
That much was true. With Yukino's personality, she'd never follow someone around like this unless she'd already accepted the situation deep down.
She hadn't wanted to become a devil, but Leo saving her life was a fact—and she'd come to terms with that. She was still struggling to adapt, still holding on to a bit of frustration, but nothing more.
Now that she truly understood how terrifying her power was, Yukino's mind began to settle.
"Whatever else happens, at least teach me how to control it," she said seriously, turning toward Leo. "I don't want this power breaking loose again."
"Don't worry—that's exactly what we're going to do next." Leo grinned. "Whether it's your demonic power or your Sacred Gear, I'll teach you how to use both."
This was his first servant—a devil with incredible potential. Letting that talent go to waste would be unforgivable.
He had a lot ahead of him—rebuilding the Eligos House, reestablishing himself as a pureblood High-Class Devil—all of which would require capable servants by his side. Yukino's growth was just as crucial to his future as his own strength.
Besides, Leo wasn't exactly ordinary either. He too bore a Longinus—one ranked even higher.
After deciding on their next steps, Leo didn't start training immediately. Instead, he led Yukino to the fourth floor of the manor, into a grand study.
Rows of towering bookshelves lined the room, packed with countless tomes—not mundane books, but ones steeped in the occult and the supernatural.
These were the Eligos House's ancestral texts, returned to Leo after he inherited the family name. Some were ancient grimoires, others manuals of demonic magic and technique passed down through generations. They contained methods of training and channeling demonic power, techniques for detection, and even spells dating back to the age of myth.
Though the collection had been damaged by the family's fall—many volumes lost or copied by other devil clans—the ones that remained were priceless, especially for Leo and Yukino, who desperately needed this knowledge.
Leo handed Yukino a book detailing demonic power training methods. "Memorize what's in here. Start by learning how to sense and control your demonic power."
He himself pulled a thick, black-bound volume from the shelf, flipping through pages about Sacred Gears—their classifications, resonance, and compatibility with demonic energy.
Sacred Gears had existed for centuries. Every major faction—devils, angels, fallen angels—had studied them in some form, and even if none matched the Grigori's expertise, they still knew plenty.
Both Leo and Yukino needed to master this knowledge to wield their Sacred Gears properly.
So the two of them decided to skip school for a few days and focus on studying in the manor.
Of course, when they both vanished from class the very next day, the rumor mill at Sobu High exploded.
A boy and a girl show up together one day—then take the same day off right after? Please. No one was buying that nothing was going on.
And since people had seen them enter the Service Club's room together and not come out, the gossip only got worse.
By the end of the week, "Eligos-senpai and Yukino's scandal" was all anyone could talk about—fueling wild theories across campus.
Not that the two culprits had any idea. Oblivious to the rumors, Leo and Yukino continued their studies in the manor.
When night fell, however, Leo refused to let her leave.
"You're my servant now," he said casually. "You might as well stay here."
Yukino immediately tensed.
"I'm getting the feeling my chastity might be in danger. So no."
Leo raised an eyebrow, his gaze flicking down briefly before he made a face of pure disdain.
He didn't say a word—but the silence said plenty.
Yukino clenched her fists. "Say it."
"I don't want to."
"Your disgusting, perverted expression already gave you away."
"Well, only if you assume I'd be that perverted."
"So you're trying to justify yourself now?"
"I'm just saying—it's important to have some self-awareness."
"You mean I'm not cute enough? That no one would ever think of me that way?"
"Don't put it like that. I'm sure someone out there thinks small is cute too."
"!!!"
That was it. Yukino snapped.
The air turned frigid as the white figure of the Ice Princess materialized behind her, radiating deadly cold.
Before the frost could spread, however, Leo lifted a hand and snapped his fingers. Instantly, the freezing energy vanished without a trace.
Yukino froze in shock. For the first time, she realized just how strong Leo really was.
That power… he canceled it so easily.
"The power of a High-Class Devil?" she murmured.
Leo just shrugged. "You're only struggling because you can't control your Sacred Gear yet."
In truth, he hadn't even used his devil power. What he'd unleashed was the might of his own Sacred Gear—Zenith Tempest.
It commanded weather and natural elements at will, including ice. Yukino's Absolute Demises, ranked eleventh among the Longinus, was a lower-tier one compared to his second-ranked power. Overriding her cold was effortless.
Of course, that was only because Yukino was still weak. She hadn't yet learned to channel her demonic power properly, nor could she draw out the full potential of her Sacred Gear. If she had, even Leo's suppression wouldn't have come so easily.
"Keep working at it," he said lightly, giving her a firm pat on the shoulder.
Yukino pursed her lips, her expression clearly dissatisfied.
Still, in the end, she stayed at the manor.
There wasn't much choice—her apartment wasn't exactly suited for training her powers.
And that night, Leo told her one more thing.
"Get ready. The meeting I mentioned before—it's about to happen."
The High-Class Devil from the Underworld who oversaw Leo's affairs was finally coming to visit.
Night descended quietly.
As the last light of the sun vanished and the world turned dark, Yukino finally understood what Leo had meant earlier that day.
The moment night fell, her body—sluggish and drained under the sun—suddenly came alive. Power flowed smoothly through her veins, and her mind felt sharp and clear, as if she'd been restored to her natural state.
It was like a fish returning to water. The darkness that once frightened her now felt strangely comforting, even welcoming. She could even see clearly without lights, her vision adapting effortlessly to the night.
Together, she and Leo headed down to the underground chamber.
There, the magic circle on the floor was beginning to glow brighter and brighter.