Honkai, why do you only throw me into high-level battles?

-Flashback-

Nagazora City ruins, ME Corp.

ME Corp's headquarters now resembled a tombstone more than a bustling corporation. It stood silent and still amidst the desolate ruins, a ghost of what it used to be.

BOOM!

A sudden crash echoed from the top floor, reverberating through the abandoned, dimly lit building. Tesla, furious, kicked down the president's office door. She stormed in, yelling, "Cocolia, get out here!"

It was a mystery how her slender legs managed such a feat with that heavy wooden door, but there was no denying her strength. Raiden Ryoma had good taste, it had to be said, but it was all gone now.

And the building's current owner, Cocolia, wasn't about to answer Tesla's call.

"Dr. Tesla, as I said, she's not here," Einstein said calmly, following Tesla into the office. It was clear she had anticipated this outcome. "Our long trip here was a waste of time and fuel."

"Hmph! Good riddance!" Tesla growled in frustration. She started rummaging through the office, her anger building. "Since she's gone, we'll strip this place bare and take everything back to HQ! Give it all back to Raiden Ryoma!"

Her fury only escalated. Looking for an outlet, she smashed the coffee table with her augmented arm. "Thanks to her, this building is worthless anyway. If she wants it so badly, she can have it!"

Einstein watched quietly, her expression unchanged. It wasn't like her to interfere. Who wouldn't be furious to discover their patents and blueprints had been stolen?

Einstein massaged her forehead, trying to hide the gesture by smoothing her hair. "Lately, it's just been…"

It all started when Lin Wei questioned them about an intel leak from Anti-Entropy. This triggered an internal investigation.

The North American HQ check went smoothly, even giving them time to monitor Schicksal and pick up on Yuno's unusual activity. They alerted Lin Wei, who then took over that investigation.

The two doctors turned their focus to Anti-Entropy. Checking the North American HQ was easy; going further afield, however, proved difficult.

Branches in Siberia, South America, and other locations resisted the HQ audit. One plane carrying auditors even crashed.

A chill ran down their spines. Anti-Entropy was in serious trouble. These branches, usually insignificant, were now actively obstructing them. Ironically, Cocolia's faction, typically a rival, cooperated—almost too eagerly.

Tesla, as stubborn as ever, doubled down. The more resistance they met, the harder she pushed. Risking a schism within Anti-Entropy, she personally led a team to oust the South American branch head and begin a thorough audit.

They found blueprints for the latest Titan model, a production line larger than HQ's, and dozens of completed Titans—not in Anti-Entropy's plans—ready for shipment. Tesla nearly fainted.

Further investigation yielded no answers. The buyer and destination were erased. The branch head? Found dead in his cell, an apparent suicide (with three Bullet in back of head). The trail went cold.

Undeterred, Tesla moved on to other branches. Suddenly, they were all cooperative, offering nothing but identical, unhelpful statements.

"…What the hell infiltrated us?" Tesla and Einstein exchanged a horrified look.

"Is Anti-Entropy… still ours?" Tesla muttered, her mind racing. How could they face Yang, Joyce, and the other comrades?

"Should we ask Lin Wei for help? His Key of Corruption would be perfect for this," Einstein suggested, her tone thoughtful. "It's a chance to test our 'friendship.'"

"Mophead, haven't we embarrassed ourselves enough in front of him?" Tesla balked. "He's already arrogant. If he sees this mess, he'll be even worse!"

Einstein leaned against the door frame, her calm gaze speaking volumes. She didn't respond verbally, but her eyes said it all.

"Fine! I know this isn't the time to be stubborn..." Tesla groaned, defeated. "I... I'll call him..."

Just as she was about to contact Lin Wei, a sweaty staff member burst in, carrying a stack of reports.

"Report! Doctors... We found something! Please review!" he panted, out of breath.

Snapping to attention, they dove into the documents.

"We've found unusual financial and personnel activity. A large sum of money and materials have been diverted, destination unknown. The source traces back to those problematic branches. And..." The employee hesitated, looking troubled.

"What other bad news? We can handle it," Einstein said, her voice steady as she saw Tesla's growing agitation.

"And... a large number of personnel have been reassigned, destination unknown... They're almost all..."

"Cocolia!" Tesla shouted, reaching the relevant page and slamming the file shut. "That vixen is behind this!"

.........

"Dr. Tesla, since Cocolia isn't here, let's go back and figure out how to contact her instead of fuming," Einstein said softly.

They couldn't keep bothering Lin Wei, could they? Now that they had found the culprit, there was no need to air their dirty laundry.

"Contact her? Easy for you to say..." Tesla gritted her teeth, clearly deflated after her outburst. "She's practically gone rogue! How are we supposed to find her?"

"Rogue? Who's going rogue?" The large wall screen suddenly lit up, revealing Cocolia. She looked surprised to see them.

"I just got an alert about intruders," Cocolia said, raising an eyebrow. "Imagine my surprise... It's you two. What a rare sight..." She seemed blissfully unaware of the trouble she was in.

"Cocolia, you..." Tesla's anger flared again. You have the nerve to show your face?!

Einstein held up a hand to stop her outburst. Tesla glared at the screen, frustration building.

"Cocolia, we have some questions," Einstein's voice remained calm. "We detected unusual financial and personnel movements linked to you. We need an explanation."

She paused for a moment, then glanced at the lush forest behind Cocolia. "Also... What are you doing now?" Einstein asked.

Nagazora City had severely damaged Anti-Entropy's reputation. They couldn't afford another incident, so Cocolia's actions needed to be monitored closely.

"Oh, this?" Cocolia waved a hand dismissively, a smug grin on her face. "I'm on an island in the Pacific. I found a Previous Era ruin, untouched by Schicksal. It's quite promising."

She leaned in slightly, clearly relishing the opportunity to taunt the old guard. "I'm overseeing things personally to avoid leaks and Schicksal interference. I hardly need to report this to you, do I?"

"You!" Tesla was about to explode again, but Einstein quickly held her back.

"If it's a newly discovered ruin, secrecy is paramount. Well done, Cocolia," Einstein said calmly.

"Why, thank you," Cocolia preened, clearly pleased with herself.

"But there's still the matter of the massive funds and materials," Einstein pressed. "Exploring a ruin shouldn't require such extravagance."

Cocolia scoffed, looking almost offended. "Emptying Anti-Entropy's coffers? What are you accusing me of now, Dr. Einstein?"

She sighed dramatically. "Unfortunately, this ruin is deep underwater, which is why it escaped Schicksal's plundering... But there's a price. Exploring it is costly, as you surely understand."

Tesla couldn't hold it in anymore. "Costly?! She's practically bankrupting us!"

Cocolia blinked, bewildered. Is the lobster-headed doctor just making a fuss again?

Einstein, ever the pragmatist, steered the conversation back on track. "Cocolia, since this has already happened, let's hope it's worthwhile. What kind of ruin warrants such an expense?"

"What kind?" Cocolia's voice rose with excitement. "Do you know where I am? I'm in the Pacific! This was Mu, a continent from the Previous Era—the pinnacle of their technology and civilization!"

She paused, gathering herself, her tone turning more serious. "My intel suggests there's a device inside the ruin, a technological marvel connected to a mysterious dimension—the Quantum Realm. Exploring it might give us new ways to fight the Honkai."

Wait, what?

Tesla perked up at the mention of the Quantum Realm, exchanging a look with Einstein. If this was true, it could be huge. Cocolia's methods were shady, but if this paid off... would they be fools to stop her?

But still... Why all the secrecy? They didn't quite understand her logic.

"...Cocolia, shouldn't we have discussed this and planned together?" Einstein asked, his voice tinged with exasperation. Why did she feel like the one trying to steal credit?

"Hmph, easy for you to say. I discovered this ruin!" Cocolia shot back, clearly intent on leveraging her position. She wasn't about to shut them out entirely, though. Preliminary surveys had shown she'd need their scientific expertise to excavate the underwater ruin.

"What more do you want?!" Tesla felt completely wronged. They'd already overlooked Cocolia's shady dealings, treating the diverted resources as an investment. Now she wanted more?

An idea suddenly sparked in Tesla's mind.

"Cocolia, haven't you always wanted something from me?" Tesla asked, a glint of mischief in her eyes.

Cocolia raised an eyebrow. "Oh? And what could you possibly offer?"

Tesla grinned, her tone smug. "My greatest design – the Padrino!"

She paused, enjoying the suspense. "The complete blueprints, even some technical guidance, so you can build it. How's that?"

Einstein shot her a side-eye, but said nothing.

The Padrino was, without a doubt, Tesla's most impractical design. It was large, unwieldy, and completely unfit for combat. Her sober calculations had proven it would need a Herrscher core to even function—and even then, it was nothing more than a pipe dream. Tesla had shelved it long ago, declaring, "If I had a Herrscher core, I'd make a Divine Key! Much more useful than this monstrosity!"

It had been her biggest design failure.

But for some reason, Cocolia was obsessed with it.

Cocolia's eyes lit up. "Are you serious?" She had wanted those blueprints for a long time. Why wouldn't they build it? Lack of courage, she concluded.

"Deal!" Tesla grinned inwardly. Let's see you build it. You'll regret it! The thought was immensely satisfying. You asked for it!

With the agreement in place, the two factions surprisingly found a cordial understanding.

Two days later, Tesla and Einstein arrived at the coast, boarding Cocolia's submarine. They descended into the depths of the Mariana Trench.

A few days later, Lin Wei, having learned of Otto's movements, tried to contact them. But they were underwater. And underwater, there's no signal.