She was a girl as pure as snow, with silver hair and crimson eyes, clad in violet attire. Her innocence radiated like the frosted fairy of legend.

Lin Luo knew she wasn't some mythical frost spirit, but a human—or rather, an artificial creation. This was none other than Illyasviel von Einzbern, the Winter Princess who had served as the Holy Grail's vessel during the Fifth Grail War.

Formed from magical circuits into her humanoid shape, Illyasviel possessed the innate gift of magic. Born with the role of Holy Grail Container preordained in her being, every circuit within her body composed the Grail itself—the heart being its core.

This unique physiology halted her physical maturation completely. Though now an adult by status, she remained a seven-year-old's form. Despite never receiving formal magical training, her abilities transcended conventional theory. Her very existence pulsed with magic that could manifest wonders without conscious intent.

During the Fifth Grail War, she had been near-Boss-level presence, surpassing even Rin Tohsaka in sheer mystical power—her Master's capabilities reaching legendary heights.

Yet for Illyasviel, life was an unending tragedy. In Lin Luo's memories, she was daughter to the "Magus Killer" Kiritsugu Emiya and the other Grail Container, Artoria Pendragon—the Einzbern princess. Though bearing royal title, she'd received no royal treatment, treated like a disposable tool like her distant cousin Angra Mainyu. Worse still for her, possessing full consciousness meant experiencing those horrors with greater clarity than her feline counterpart.

In canon, after the Fourth Grail War's conclusion, with Kiritsugu's betrayal shattering their last hopes, the Einzberns placed all expectations on this seven-year-old girl. Left to endure childhood in isolation, without familial warmth.

How could a child so young bear such crushing destiny when her father had slain her mother before her eyes? The tender memories of past happiness twisted into poison, birthing curses against fate itself. Only by mastering Berserker through hellish trials—without losing sanity or dying—could she glimpse redemption.

Madness became her survival mechanism, the only force keeping her alive in daily torment. Her angelic visage belied a cruel existence: beautiful as snow yet vanishing before it could truly bloom.

In canon, every soul held potential for salvation and happiness... except Illyasviel. No matter choices made or efforts exerted, one path remained inevitable—death.

"Big brother, who are you?" The girl approached with no trace of fear in her bright eyes, skipping forward as if greeting an old friend rather than a stranger.

"Lin Luo," he replied just as Rei arrived, stepping into view with that familiar gentle smile.

"Eh? Auntie Rei knows this big brother?" Illyasviel tilted her head cutely, her mental age mirroring her physical one at six-seven years. Her innocent curiosity sparkled like fresh-fallen snowflakes.

Rei nodded warmly, clearly charmed by the girl's pure demeanor.

Lin Luo smiled back before crouching to Illyasviel's level. "Yes indeed. What's your name?" he asked.

"Illyasviel von Einzbern," she declared proudly while sticking out her tongue playfully. "But you can just call me Illyasviel, too long names aren't fun."

Ah—shared aversion to long titles. Lin Luo noted the parallel between Rei and this girl. Though their meeting's origins remained unknown, their artificial natures connected them meaningfully: one a weapon-born existence, another an engineered human. One as pure as snowflakes; the other as vast as sky.

"Then I'll call you Illyasviel," Lin Luo decided. "Is this Einzbern Castle?"

Though unsure how he'd arrived here, passing through the neutral zone and Millennium City made accessing Einzbern trivial.

"No..." she shook her head, pointing toward snowy wilderness where only white expanse remained visible. "My home's there... Papa and Mama left a while ago, I miss them very much. But Grandpa says not to leave, and I promised to wait patiently. So I'm sneaking out for some fun..."

Her voice dwindled at the end, self-conscious about her escapade.

Lin Luo had wondered why Einzbern would let a child wander freely in their domain—until now.

"Illyasviel," he asked carefully, "your parents... how many were there? When did they leave?"

Kiritsugu Emiya represented his greatest potential adversary. Extracting intel from his daughter felt morally ambiguous, but considering Kiritsugu's willingness to murder his own wife for ideals...

"Three people—Papa, Mama, and the pretty big sister—left three days ago," Illyasviel counted on her fingers clearly remembering their departure.

Lin Luo paled. Three days? The Grail War had already begun then! And that "pretty big sister"... Saber was definitely taken by Kirits

...Three days since the Einzberns left for Fuyuki. That meant the first servant conflicts occurred three days ago—the precise start of the war.

Lin Luo's mind raced. Only a week long max, four to five days at most. Three critical days had already elapsed.

He needed to return immediately.

"Thank you Illyasviel," he said urgently. "We must go now."

"No! Big brother doesn't like me? That's why you're leaving and don't want Auntie Rei to play with me?" She looked devastated, fidgeting with her dress hem anxiously.

"Of course not," Lin Luo soothed gently patting her head. "I really do care for Illyasviel, but I have something very important to do."

"How important?"

"As important as..." He hesitated before answering firmly. "...as my life itself."

"Tch, then I won't be sad." She brightened suddenly. "But will big brother and Auntie Rei come back to play after you finish your important thing?"

"Yes," he promised, exchanging a glance with Rei who nodded in agreement.

"Really? Then pinky promise!" She extended her tiny hand cheerfully.

"Pinky promise," Lin Luo chuckled despite himself, unwilling to spoil the child's excitement.

"Ahhh big brother, before you leave... give me something special as parting gift?" He paused mid-step after sealing their pact.

"What kind of gift?"

He simply held out his hands.

"Nothing there!" She tilted her head in confusion at the empty palms.

"Close your eyes."

She obediently shut them tight.

Then Lin Luo placed both hands over her forehead, murmuring: Holy Healing—Muscle Reinforcement... Complete... Skeletal Fortification... Completed...

Though Illyasviel was a natural prodigy as Grail Container, without training she remained just an ordinary child. His healing magic would still benefit her immensely here—especially when enhanced by rule-based abilities rather than raw power.

Five minutes passed. Lin Luo spent two-thirds of his vitality reinforcing most of her physical structures. While not enough to change her fundamental constitution, it might lessen future suffering if circumstances allowed.

Actually, he had considered taking her away completely. But facing Kiritsugu as enemy... How could she handle that? And even with victory uncertain against Gold Saber or Angra Mainyu...

Better leave her here for now. If he failed, nothing more mattered. If succeeded, rescuing her later would be simple—Einzbern held no real threat to him.

"Big brother and Auntie Rei goodbye! Illyasviel will wait!" The snow-like girl waved repeatedly with radiant smile as they departed.

Goodbye, Illyasviel. But I'll definitely keep this promise.

Lin Luo vowed silently before leaving with Rei. Along the way he asked about her experiences during his absence...

It turned out Black Queen had thrown him into Millennium City deliberately to corrupt White Queen through blood bonding. During that time, Rei was entrusted to White Knight's care.

Normally such secrets would remain hidden from Rei—but she pressed questions relentlessly every few minutes. If this were an enemy, White Knight could simply vanish them all with Phantom March. But against Rei...

Beat her? Ignored.

Scolded her? Disregarded.

Got angry? Still questioned.

Eventually, exasperated by relentless interrogation, White Knight just spilled everything.

Rei immediately insisted on finding Lin Luo. Of course, White Knight refused...

They deadlocked for two weeks until that... PK Showji kid distracted White Knight. Rei exploited the moment to escape into wilderness, where her unfamiliarity with terrain led her straight into Einzbern's domain by accident. Just as Lin Luo had imagined—lost in snows, she met Illyasviel. Their shared artificial natures and similarities made instant friendship possible.

Lin Luo sighed at the absurdity.

Upon learning everything, he cursed Black Queen's underhandedness while thanking that PK Showji character—whoever that was—for his distracting powers. Also marveled at Rei's survival skills as she wandered alone for two weeks unscathed by perverts—proof of her protagonist aura.

Two hours later they boarded Japan-bound flight. Though lacking passport, Lin Luo had no trouble arranging it with current abilities.

Rei slept through most of the flight while Lin Luo replenished vitality with complimentary airplane food.

Fuyuki lacked direct flights so they landed in nearby city. Though eager to return, Lin Luo accepted the detour calmly.

Several hours later at station, still sleeping Rei was carried onto train when—

*Crash!*

Lin Luo collided with an older man who froze mid-step as if struck by lightning.

"...Huh?" Thinking him just startled, Lin Luo turned away until—

The man suddenly lunged like a rabid animal!

Dodging easily, Lin Luo's eyes narrowed upon noticing two fangs protruding from his lips. No full vampire markings, but the wildness in expression... Bloodlust?

"Rule Force: Teleport!" He vanished then reappeared inches before target, finger piercing through coat and heart instantly sealing wound.

Fast enough that no one saw the attack except witnessing the man collapse moments later on train platform as it departed.

A wailing elderly woman with twin grandchildren rushed forward.

"Master Shinjo! How could you die just now? You were about to take these poor orphans home..." She sobbed dramatically, name triggering vague familiarity...

Shinjo... The name nagged at Lin Luo's memory.

Whatever. Another disposable extra, he decided, dismissing thoughts as he settled into seat for rest.

...

Meanwhile in nearby town that night—

Four figures stood beneath moonlight in quiet forest clearing: Misaka Shizuri, Tokiomi Tohsaka, Minami Kuroshio, and Houki Senkawachi.

"Ready to begin?" asked Houki.

"Almost," Tohsoka nodded, checking magic energy surging through her hand. "I can feel power reaching peak levels. Yesterday tracking magus presence in Fuyuki confirmed war has started. Though Lin Luo hasn't returned yet..."

"We'll wait nearby then. This part is yours to handle."

Nodding, Tohsoka traced runes into earth before pausing mid-spell. Normally Saber wasn't summoned through Grail War system and thus shouldn't respond—but perhaps as in other worlds...

"Return once more... Answer my call! Strongest of the Sword Seats—SABER!"

The incantation finished just as train arrived at Shinjo's body, lights flashing dramatically from rune array and her command seal glowing in tandem with it.

"Rin, I once again confirm that you truly are the most exceptional MASTER."

Standing with sword in hand, the girl radiated confidence at the center of the magical array. There, she embodied a knight of pure white reaching perfection within fantasy—the noble and chaste monarch who had once protected everything through sheer willpower. From fiction to reality, this moment marked the return of the strongest spirit from the Seat of Swords to this world.

Not mere imagination, but authentic selfhood.

"Welcome back, SABER..." Two lines of tears streamed down Rin's cheeks as she wept for the joy of reunion.

"Rin... Wait?" The regal snow-white knight blinked in sudden shock upon seeing Rin's current form, eyes wide with disbelief before abruptly...

"How adorable—come here so I can pet you..." With a clatter of Excalibur dropping to the ground, the noble hero launched herself toward the midget Rin.

"Waah, SABER what are you doing? You're pinning me down!"

The little Rin squirmed desperately beneath her, writhing back and forth...