Yukino had never forgotten how she lost to Sharon.
Back then, after she unleashed the full power of her Longinus, Sharon had been forced into what looked like a corner, barely holding on under Yukino's relentless assault. Just as Yukino prepared to deliver the finishing blow, Sharon revealed her hidden trump card, making it clear that all her earlier struggle had been nothing more than an act to secure final victory.
She had been quietly preparing a decisive counterattack the entire time, enduring everything until the very last moment. Then she played her ace—activating a light-based Magic Formula designed to annihilate devils, completely overturning the situation and nearly purifying Yukino on the spot.
That was why Yukino couldn't let that battle go.
It wasn't that she couldn't accept defeat.
What she couldn't accept was being played.
From that day on, Yukino trained even harder than before. She buried herself in books as well, nearly reading through the entire Eligos family collection, learning countless useful things along the way.
And for the sake of washing away that humiliation, she prepared something just like Sharon had.
When Sharon—her entire body wreathed in black aura, gripping two vicious-looking blades—raised her weapons to deliver the final strike, her body suddenly froze.
"Th-this is…?!"
It wasn't that she wanted to stop.
She realized she couldn't move at all.
That's when Sharon noticed the surroundings had changed.
The room, which had already been frozen into an icy wasteland by Yukino's Sacred Gear, was now filled with ice-blue magic circles that hadn't been there before.
They spread out silently, releasing an astonishing chill. Wisps of white, mist-like frost crept outward without a sound, blanketing the entire frozen world.
Compared to the freezing air produced directly by Yukino's Sacred Gear, this chill seemed insignificant. It lacked the power to freeze everything instantly, and it wasn't strong enough to whip up a blizzard.
But once it spread everywhere, the atmosphere itself felt as if it had solidified into ice, making even the smallest movement feel impossible.
Frost gathered around Sharon as well. Without realizing it, she found it increasingly hard to breathe, as if the oxygen she inhaled was woefully insufficient. Her body began to weaken, deprived of air.
"So… it finally worked?"
Seeing this, Yukino exhaled and smiled.
"What did you do…?"
Sharon forced the words out, her chest feeling like it was about to burst.
"What did I do? Isn't it obvious?" Yukino straightened herself with effort and looked at Sharon. "When you saw those magic circles, you should've guessed, right?"
"After all, you did the exact same thing last time. Didn't you?"
As Yukino spoke, a massive magic circle gradually appeared on the ground, completely enveloping Sharon's position.
"You… when did you…?!"
Sharon's expression finally changed.
She understood exactly what Yukino had done.
Just like herself before, this woman had looked like she was being driven into a corner, when in reality she had been secretly drawing magic circles the entire time, preparing a Magic Formula meant to turn the tables at this very moment.
But how was that possible?
Just because Sharon could do it didn't mean someone else could do the same.
At the very least, she was certain that if Yukino had been doing something underhanded during the fight, she would have noticed.
Yukino was nothing more than a newly reincarnated devil of only a few months. Her perception was limited, her experience lacking. That was precisely why Sharon had been able to prepare her own reversal right under Yukino's nose without being discovered.
But Sharon herself?
She was a veteran who had survived countless battles, large and small. How could she possibly fail to notice the hidden preparations of a reincarnated devil?
And she was sure of one thing—just moments ago, Yukino really had been pushed to the brink. There was no way she could have secretly prepared anything.
So where did these magic circles come from?
It was as if Yukino could read Sharon's thoughts.
"True. Unlike you last time, I wasn't pretending to be cornered. You really did push me to my limit," Yukino said calmly. "By all logic, I shouldn't have been able to secretly prepare anything under your watch."
"But just because I didn't do it doesn't mean this child didn't."
As she spoke, Yukino raised one hand. The surrounding frost surged.
The next instant, from within the mist-like freezing air, a small, crystal-clear cat appeared, leaping onto Yukino's hand and settling there.
"That's… an Ice Spirit?"
Sharon recognized it at a glance.
It was the familiar Yukino had contracted in the Familiar Forest—the Ice Spirit she named Fuyufuyu.
"I only realized it after forming the contract," Yukino said softly. "As an Ice Spirit, Fuyufuyu doesn't just match my attribute perfectly. She can also harmonize with nature… or rather, completely blend into ice and snow."
"She becomes part of it, helping me control the power within the ice and snow, expanding its range and effectiveness."
Yukino gently stroked Fuyufuyu's body, a faint smile appearing on her pale face.
"That's when I started wondering… if I could have her help me draw magic circles within the ice and snow, preparing a Magic Formula to turn the tables."
"The magic circles you see all around us now? That's where they came from."
They weren't prepared by Yukino.
They were prepared by her familiar.
From the very beginning, Yukino's reason for contracting a familiar had been to strengthen her combat ability.
Back in the Familiar Forest, she had given up the more powerful frost dragon and chosen the Ice Spirit Fuyufuyu instead. And now, it was clear that the sense of closeness she'd felt back then—and the choice she made—had both been right.
Fuyufuyu might not match a frost dragon in raw power, but her ability to assist Yukino's abilities and Magic Formula was no less valuable.
"These Magic Formula were specially prepared just for you," Yukino said, pointing at the magic circle beneath Sharon's feet. "I practiced them for a long time."
"The surrounding magic circles continuously produce ice powder so fine it's invisible to the naked eye, mixing it into the air. When you breathe it in, your lungs are already slowly freezing."
"That freezing spreads to every corner of your body. Once the ice powder covers you, you'll gradually be frozen solid—until you can't move at all."
"And as for the one beneath your feet…"
Yukino paused. "It has only one effect."
She activated the Magic Formula within the magic circle. The surrounding frost was drawn in as if by an invisible vortex, continuously pouring into it.
Ice-blue light flared within the magic circle, growing brighter and stronger with each passing moment.
"All the frost filling this space will be absorbed and compressed to the absolute limit."
"When it reaches the critical point, it'll be released all at once."
"So why don't you guess?" Yukino said quietly. "After compressing this much frost to its limit… which do you think is stronger—this, or the Magic Formula you used last time?"
Looking at Yukino's pale face as she smiled, Sharon felt something inside her snap.
"Yukino…!"
The nun let out a hoarse scream, only to cough up blood midway through.
Her blood was mixed with shards of ice—it was obvious her body had already been filled with frost.
She tried to move, tried to swing the Devil Slayer in her hands, but she still couldn't move at all. Every attempt only brought pain.
"Even if I had to use a bit of strategy to stall for time," Yukino said, her expression firm, "the result is still my victory."
She looked at Sharon, a trace of complicated emotion flashing through her eyes before quickly disappearing.
"This is me returning the favor from last time. Take it head-on."
The moment her words fell, the ice-blue light within the magic circle beneath Sharon's feet reached its limit and began to overflow.
"Boom!!!"
In the next instant, an ice-blue pillar of light shot skyward, plunging the entire space into subzero temperatures and swallowing Sharon whole.
The pillar was made of frost compressed to the extreme. The moment it appeared, the ground around it froze at a terrifying speed.
When the pillar reached the ceiling, the ceiling froze as well, connecting with the ice on the ground. Frost gathered along the walls, turning the entire room into an ice cavern where nothing but ice could be seen.
Yukino slowly lowered her hand, her weakened body leaning back against the wall once more.
She gave a faint smile.
Beside her, Fuyufuyu licked the blood and wounds on her arm, making her wince slightly.
"I'm fine. Don't worry."
She patted Fuyufuyu's small head and forced herself upright again.
"…That's the way out, right?"
She noticed a passage where there hadn't been one before, took a deep breath, and after a short while began to move.
One hand pressed against her abdomen, the other braced against the wall, Yukino slowly made her way toward the dark, bottomless passage.
Behind her, the ice-blue light faded away and vanished completely. In its place stood a massive ice pillar in the center of the room. The magic circle beneath it disappeared as well, as if it had never existed.
Inside that ice pillar, the nun clutching her vicious blades was frozen like an ice sculpture.
The sight of it was… strangely beautiful.