---Flashback---
One week earlier, in a desolate, abandoned village half-buried in the sands of North Africa, Lin Wei sat behind a crumbling wall, sheltering from the harsh midday sun.
Ssk... ssk... ssk...
A faint, rustling sound reached his ears, like someone rubbing a handful of sand between their palms. Lin Wei followed the sound and saw a massive "serpent" burrowing through the nearby sand, leaving a clear, winding trail as it approached his position.
Poof...
With a muffled pop, the "serpent's" head burst from the ground, sending sand flying everywhere. Lin Wei had to shield his eyes. When he lowered his arm, a disheveled, gray-haired girl stood where the "serpent" had been, frantically patting herself down.
"Cough, cough... Ptooey, ptooey!"
Yuno felt like her mouth and nostrils were full of sand, not to mention her hair, clothes, and shoes. It was incredibly uncomfortable.
She'd never imagined that right after leaving the orphanage and starting to re-familiarize herself with her powers, Lin Wei would give her such a strange request.
"Imagine you are the roots of a great tree, burrowing deep into the dark, profound earth..." Lin Wei had said, gesturing at the endless desert around them. His tone wasn't harsh, but it left no room for argument.
"From today on, this is what you will practice."
"Ah? Oh..."
Yuno had nodded, not quite understanding. She extended her newly reawakened tendrils, trying to dig into the sand, and thus began her life of literal darkness. She was even starting to get used to the sensation of being completely inundated with sand.
"Great progress. Not bad," Lin Wei said after Yuno had expertly buried herself again. He pointed at the winding trail she'd left behind. "But the signs are still too obvious. You need to keep at it."
He handed her a bottle of water. "Take a short break, then continue."
"Oh..." Yuno nodded, a little dejected. She took the bottle, hesitated, then rinsed her mouth and quickly washed her face with it.
Lin Wei just smiled and handed her another bottle, not scolding her for wasting precious drinking water in the desert.
Her refusal to accept small discomforts was a sign that Yuno was no longer as numb as she used to be. She was truly beginning to embrace the warmth of life. Lin Wei was happy to see this change.
"This is the first time I've seen you be so strict," Yae Sakura's form materialized out of thin air. She tenderly helped Yuno clean herself up while shooting Lin Wei a sideways glance.
"Or rather, the first time I've seen you be so strict with someone else..."
Though Lin Wei usually seemed as lazy as a salted fish, even a bit of a slacker, she knew that when he got serious, he was as precise as a machine and as autocratic as a tyrant.
But until now, he had mostly used this trait to push himself or to "persecute" distant targets he could exploit. He had never used it to demand anything of those close to him.
This was a first...
"I have no choice. There's only one chance, so we can't afford any mistakes," Lin Wei shrugged, looking innocent. Then he grinned.
"Since you're here, why don't you practice too?"
"..."
Yae Sakura sighed in resignation. She knew he wouldn't let her off the hook.
But since he'd already said it, could she refuse?
She shot him another glance and, with a ripple like clear water, transformed into an exact replica of Yuno, though her clothes were pristine, a stark contrast to the real Yuno's disheveled state.
"..."
No matter how many times she saw it, Yuno's expression was still complicated whenever someone transformed into her right in front of her.
"Never mind. This isn't something you can master in a hurry," Lin Wei said, his heart softening as he saw the uncomfortable look on Yae Sakura's face, even in Yuno's form.
"If the imitation is too deliberate, it'll be counterproductive and easier for Schicksal to spot a flaw—especially with that Rita, whose nose is as sharp as a dog's..."
Yae Sakura, relieved, changed back to her original form. But Lin Wei's leniency made her feel a little guilty. "But, in that case..."
"It's fine. Just play it by ear when the time comes. You can do it," Lin Wei reassured her.
"Just like in Manila, rely on your impression of her and improvise. Besides..." Lin Wei glanced at Yuno and smiled.
"Yuno has changed a lot herself, which will be confusing enough."
He knew that Otto didn't have many people he could deploy against him. So, when he revealed himself to Schicksal again, Otto would most likely send Rita to make contact and probe him.
At that time, without any special arrangements, she would naturally notice the changes in Yuno.
And after the initial surprise, when Yuno was switched out, the abnormalities in the imposter, while still obvious, wouldn't be as conspicuous due to the pre-existing impression...
As long as she wasn't exposed immediately, as long as she could buy a little time, Lin Wei's objective would be achieved.
He had already laid out his plan for Yae Sakura and Yuno in detail long before.
---||---
"If I were Otto, I would definitely use the Second Divine Key to banish the Key of Corrosion and its wielder into the Sea of Quanta. It's the most feasible and safest method."
One moonless night, the three of them sat around a campfire, Yae Sakura and Yuno listening quietly as Lin Wei explained his plan.
"And Anna is the perfect bait he'll use to lure me into this trap—and that's where our opportunity lies..."
"What do we need to do?" Yae Sakura asked. She knew that if Lin Wei was saying this, he already had a complete plan. She just needed to cooperate and execute it.
"Sakura, do you remember what happened in Manila before the Honkai Eruption?" Lin Wei smiled at the pink-haired girl, her features illuminated by the firelight.
"Overseer Otto himself showed up, disguised as Yuno, to achieve some ulterior motive. Since he can do it, we can certainly give him a taste of his own medicine."
As he spoke, both their gazes fell on the "subject" who wasn't the subject...
"Me?" Yuno looked bewildered. What does this have to do with me?
"...Alright, I see what you're planning," Yae Sakura smiled wryly. After spending so much time with Lin Wei, they had a deep, unspoken understanding, and she easily grasped his intentions. But at the same time, she grew more worried.
"But, if you do that, what about you...?"
She was an extension of Lin Wei's power. If she acted alone, Lin Wei would become exceptionally weak and vulnerable.
"That's the second thing I need you to do, Sakura," Lin Wei said seriously.
"With the Key of Corrosion in my hands, Otto won't dare to act rashly against me. When he does move, it will be to banish me completely. At that moment, I need you to strike unexpectedly and disrupt his plan."
Lin Wei solemnly handed the Third Divine Key to Yae Sakura. The firelight reflecting in his pupils flickered with a hint of madness and ruthlessness.
"If necessary, you can even use it to destroy the Second Divine Key entirely!"
Using the Third Divine Key, renowned for its destructive power, to destroy the cumbersome, target-like Second Divine Key would be almost effortless.
Lin Wei recalled the first time he'd seen the Third Divine Key. In his hands, it had been disobedient, but the moment it fell into Yae Sakura's grasp, it was as if it had returned to its true master, both exultant and exceptionally well-behaved.
The idea for his current plan had begun to form then—a plan that was extremely risky, but with the power of the Third Divine Key, entirely feasible...
"...Alright." Yae Sakura nodded helplessly. She knew she couldn't argue with him.
"Good."
Since Yae Sakura agreed, Lin Wei didn't say more. He turned his gaze to the confused Yuno.
"Later, I can give you a more detailed explanation privately. But first, I need you to understand what your mission is."
Seeing Yuno straighten up and focus, Lin Wei nodded in satisfaction and said succinctly, "I need you to disappear at the right moment—hide in an unknown corner and act as an off-site support, ready to provide assistance at the most critical time."
Seeing Yuno still looked confused, Lin Wei began to elaborate on his plan.
Otto's goal was simple: to banish him and the Key of Corrosion to the depths of the Sea of Quanta.
His goal was also simple: to snatch Anna from Otto's grasp. That being the case...
"If Otto can use Anna as bait to catch me, this 'fish,' then I can play along and use myself as bait to create an opportunity for you."
Lin Wei said. He had always believed that a card's effect is greatest when it's kept hidden until the perfect moment.
Therefore, while the existence of the Key of Corrosion had become common knowledge over time, serving as his overt "nuclear deterrent," he had always kept Yae Sakura carefully hidden, viewing her as his "ace in the hole" for a surprise victory.
Because of this, very few people in the world knew of Yae Sakura's existence. Many knew Lin Wei had a strange Stigmata, and many knew he was often seen with beautiful women in Singapore, but no one had ever connected the two.
And now, since he had decided to have a final showdown with Otto, it was time to reveal this last "ace." Thus, beyond the Third Divine Key and the conflicting intentions of Otto and himself, the unknown Yae Sakura became the third core pillar of Lin Wei's plan...
"Yuno, when the time comes, Sakura will disguise herself as you and get close to Anna, looking for a chance to launch a surprise attack. You, under Sakura's cover, will hide completely, wait patiently for the right opportunity, and then strike just as unexpectedly to rescue your friend from the encirclement of Schicksal's Overseer and two S-rank Valkyries!"
Lin Wei painted a fantastic picture for Yuno with his impassioned words, and her heart pounded with excitement. She nodded firmly.
"Okay!"
And so began her long and arduous "specialized training"...
Lin Wei's justification was sound.
"In the desert, besides the sand itself, where else can a hunter hide? Your abilities are related to plants, so 'drilling' into the ground shouldn't be too difficult for you."
In truth, Yuno wasn't easily swayed by verbal manipulation; even Otto had been helpless against her.
But over time, Lin Wei had built up a deep well of trust in her heart. Combined with her concern for her friend's safety, this mixture of motivation and pressure led Yuno to agree to this seemingly absurd plan without hesitation, throwing herself into the tedious and painful training without complaint...
---||---
And so, the days passed. Lin Wei watched as Yuno became able to burrow deep into the sand at incredible speeds, erasing all traces of her presence.
In the process, her own powers were considerably strengthened.
Though still not as strong as she once was, she was far more powerful than when she had just left the orphanage.
At that point, Lin Wei was finally satisfied. He called a halt to her training. After a brief night's rest, he took her aboard the aircraft projected by Rita, flying toward the distant sea, embarking on the final leg of their journey.
And so, the clock began to turn...
When he and Yuno disembarked in an Egyptian port city, a small, completely unexpected encounter led to Rita's unsurprising appearance. Unsurprisingly, she was surprised by the changes in Yuno and subtly tested her several times.
But no matter how Yuno's mind had changed and grown, she was still herself. Rita's tests naturally yielded no other answer. And so, before anything had even begun, the plan had quietly moved to its second stage...
When Rita brought Lin Wei and Yuno aboard the transport plane to Schicksal's North African experimental base, Yae Sakura and Lin Wei finally had their moment to act.
As the transport plane landed and sand swirled into the open cabin, forcing everyone inside to shield their eyes, Lin Wei discreetly projected a sliver of the Third Divine Key's power.
Yae Sakura seized the opportunity, appearing in an instant and delivering a time-freezing slash!
Time was frozen for a moment. Yuno used this chance to slip out of the transport, burrowing deep into the ground like a tiny seed.
Yae Sakura then transformed into her, appearing where Yuno should have been.
And so, when time resumed and everyone lowered their hands from their faces, though nothing had yet begun, everything was already over...
For the rest of the time, Lin Wei deployed his forces on three fronts, laying a net, watching and playing along with Otto's various performances.
He waited patiently for Otto to bare his final fangs before suddenly closing the net, ready to reap the fruits of his victory.
Why go through all this trouble? The answer was simple: Durandal.
She was the biggest uncertainty. If she joined the fight between Yae Sakura and Rita, it would introduce the most uncontrollable risk to the plan.
But if Otto attacked first and showed his hand, things would be different. The power of corrosion was too dangerous; Otto would have to prioritize keeping Durandal by his side for protection.
After all, compared to his own safety, both Yuno and Anna were insignificant at that moment. And that was precisely Lin Wei's goal!
He had seen Otto's weakness and seized his vital point. Using the strategy of Tian Ji's horse race, he used himself, this worthless "inferior horse," to firmly tether Durandal, the undisputed "superior horse," in place.
She was forced to watch as Rita, the "middle horse," was pushed back step by step by Yae Sakura, the enemy's "superior horse"...
And so, Lin Wei put himself in danger, successfully neutralizing Otto's greatest strength at minimal cost, creating a "local advantage" that should have been impossible!
Then, Yae Sakura's thunderous strike split the earth. The surface sand poured into the small, underground world through the fissure.
Yuno, under the cover of the flowing sand, quietly approached the battlefield, suppressing her eager impatience, waiting for the perfect moment to strike.
Finally, Yae Sakura sent Rita flying with a single strike, successfully grabbing Anna. As planned, she threw her toward the fissure. Yuno's eyes lit up, and she unhesitatingly shot out her vines, catching the falling Anna, who looked like an angel with broken wings.
"Success!"
She couldn't help but feel a surge of joy. She pulled Anna toward her as fast as she could, preparing to retreat with her as Lin Wei had instructed.
But the unexpected always arrives uninvited.
Just as Yuno's tendrils were about to carry Anna into the still-thick waterfall of sand, a massive, brilliant fireball shot out from an inconspicuous corner, striking the delicate vines with swift precision.
Compared to the fireball, the vines seemed incredibly fragile, and they were instantly scorched and severed!
"Ugh..." Yuno cried out in pain, shock, and anger. Who was that?
The next second, from the same inconspicuous corner, a dark figure shot out like a black lightning bolt, snatching the falling Anna into its arms!
Only then did this sudden intruder stop, its ghostly figure finally revealing itself. It was a girl in black armor, wearing a menacing mask. Her gray hair was cut short, and her posture was as straight and tall as a man's.
"..."
With her prize secured, Fu Hua shut down the power core of the Shadow Knight: Moonbeam battlesuit.
The dazzling, violent orange glow on the armor slowly faded, returning to a quiet, deep blue like the night moon, much like its wearer—calm, restrained, and finished.
"So, it has come to this after all?"
Fu Hua removed her mask, her expression complex as she glanced at the still-confronting Lin Wei and Otto. She then looked down at the girl in her arms, this Anna Schariac, another innocent soul dragged into this vortex...
"Sir Lin Wei, you're not the only one in this world who knows how to keep an ace up your sleeve!"
Seeing his secret weapon succeed, Otto was momentarily triumphant. He looked up at Lin Wei, still in the sky, and laughed.
"After all, when it comes to you, I would never dare to underestimate you in the slightest!"
"You May Have Outsmarted Me, But I Outsmarted Your Outsmarting!"