News of the Herrscher of Thunder's sudden rampage quickly reached the Newborn World Serpent Headquarters.
By then, she was already tearing across the Mu Continent at an almost incomprehensible speed.
There was little doubt about her objective.
"She's trying to destroy our technological hub."
The Newborn World Serpent had been preparing to officially launch the Herrscher Crusade that very day.
No one had expected one of their primary targets, the Herrscher of Thunder, to make the first move.
If her rampage continued unchecked, it would not take long for the Mu Continent to be completely devastated.
And if that happened, human civilization in the current era would be pushed into a truly desperate position.
Whether it was the Sea of Quanta Portal used to observe World Bubbles, or the aerospace technology that would eventually carry humanity beyond Earth, both depended heavily on the Mu Continent's technological foundations.
In real-time strategy terms:
The enemy was attacking their research center.
There was no room for delay.
"Move out immediately!"
Inside the Headquarters Base, Kevin had every combatant participating in the operation equip the new special communication devices developed by Vill-V.
Then, in a low voice, he continued:
"As we planned, while we hold back the Herrscher of Thunder…"
"First, destroy all three thousand Undersea Temples."
Most of those present responded in unison.
Even Kalpas, who usually had little patience for indirect methods like this, gave a slight nod.
The situation had become too urgent for everyone to gather inside the virtual conference room and debate the matter at length as they had before.
This time, all non-combat personnel would be evacuated to secure areas in advance.
Every available defensive force would then be freed for deployment.
And less than three minutes after Kevin gave the order…
"Everyone is assembled."
Inside the Newborn World Serpent Headquarters Base, the combat personnel stood gathered behind two figures.
MEI.
And Prometheus Prime, who carried the Void Archives.
Even Kevin, holding the Judgement of Shamash, stood among the main force.
There was no need for some impassioned speech before battle.
They simply did not have the time.
Every minute mattered.
Every second mattered.
And truthfully, none of them needed such formalities anyway.
So there was only one sentence.
"Then I'll leave the rest to all of you."
MEI's expression was solemn.
She had already equipped the modified Key of Blankness.
Without waiting for a reply, she acted.
Hum…
The rotating mechanism built into the armor's chest shifted into position.
The golden-orange Herrscher Core lit up.
For the first time, MEI activated the Key of Blankness and switched into the usage mode corresponding to the Authority of the Herrscher of the Void.
Immediately, the armor's appearance changed.
Its original white base and black detailing were replaced by a golden-orange color scheme matching the activated Herrscher Core.
Then…
Whoosh, whoosh, whoosh…
Dozens of spatial gates opened simultaneously, each leading to a different location across the Mu Continent.
MEI frowned slightly.
This was her first time wielding the Authority of the Void directly, and she was still adapting to the unfamiliar sensation.
Several of the coordinates were slightly off.
Fortunately, her rate of improvement was astonishingly fast.
Much like in the original historical timeline, when she had faced the Herrscher of Domination.
There was another issue as well.
Pressure.
The burden placed on an ordinary human body by forcibly turning it into a temporary Herrscher.
For a normal person, enduring that strain for even several minutes could result in severe and irreversible damage.
Fortunately, MEI was no longer the ordinary researcher she had been in the original historical timeline.
She had already stepped onto the Path of Erudition.
On top of that, the current Key of Blankness had undergone several improvements based on its original design.
That level of optimization had never been possible in the original timeline.
Back then, by the time the Key of Blankness was completed, humanity had already reached the final phase of the Tenth Honkai Eruption.
Eighty-five percent of the world's cities had been destroyed.
There had been neither the time nor the resources for further refinement.
Now, however, the Void Archives had been recovered, and both the Herrscher of Reason and Herrscher of the Void Cores were available.
Only under these conditions could the optimized Key of Blankness truly be completed.
With all of those advantages combined, the strain remained within MEI's tolerance.
"I can sustain combat for an extended period."
She reached that conclusion almost immediately.
At the same time…
Whoosh, whoosh, whoosh…
The large number of combatants standing behind her began moving.
Kevin.
Elysia.
Kalpas.
Even Kosma.
And many others.
Whether Sim or original, nearly every powerhouse capable of fighting at the Herrscher level entered one of the spatial gates.
Soon, only a few remained behind MEI.
Rows upon rows of Girl Dolls.
Aponia.
Fu Hua.
Sim Hua.
And Sakura, carrying Jizo Mitama.
Whoosh…
MEI closed the dozens of portals.
Most of the Newborn World Serpent's high-end combat forces had now been deployed across key locations throughout the Mu Continent.
All of them remained connected through the newly established special communication network.
The moment anyone encountered the Herrscher of Thunder…
"Do not try to defeat her."
"Delay her for as long as possible."
"Sakura will deliver the decisive strike."
This was the plan they had agreed upon in advance.
A last resort.
Among everyone currently within the Newborn World Serpent, Sakura remained the fastest MANTIS.
Unfortunately, although her trump card, Blink, was fast enough to catch even Kevin completely off guard the first time he witnessed it, it could only briefly surpass the Herrscher of Thunder's extreme speed over a short distance.
Sakura was incapable of sustaining that speed across a prolonged chase.
Because of that, she would need the cooperation of her comrades to restrict the Herrscher of Thunder within a manageable area.
Only then could Sakura use Jizo Mitama to deliver the finishing blow.
Before that, however…
"Begin, Prometheus."
"Yes, Doctor."
Behind MEI, the neatly arranged Girl Dolls moved in perfect unison.
Whoosh…
MEI, temporarily wielding the Authority of the Void, opened another large series of spatial gates.
The golden-orange portals appeared and vanished in rapid succession.
Every time one opened, the scenery beyond it revealed a different region somewhere across the world.
Yet every destination shared one thing in common.
Snow.
Endless white snow.
Frozen landscapes.
A world gripped by bitter cold.
Into those locations, the Headquarters Base deployed fully prepared Girl Dolls one after another.
As components of the super-artificial intelligence known as Prometheus, they shared a single unified consciousness.
Unfortunately, because production had been rushed, their current Omnic bodies could only temporarily display combat power approaching that of an ordinary Herrscher.
Even so, that was enough for the mission assigned to them.
Their task was to break through the defensive perimeter surrounding each Undersea Temple.
Then, during the crucial three-minute-and-thirty-three-second interval established through previous testing with Elysia, they were to simultaneously destroy the building complexes serving as the sources of the Cold Wave.
By self-detonation.
As completely as possible.
All at once.
As for the rising sea levels that would follow…
The Newborn World Serpent had already accounted for that.
In fact, there was more than one reason they had delayed official action until after the Cold Wave had spread across the entire planet.
They needed time.
Time to produce enough self-destruct units.
Time to finish the Key of Blankness.
And time for the environmental conditions to shift far enough that the destructive consequences of the coming floods would be reduced naturally.
Had they destroyed all of the Undersea Temples immediately after the Cold Wave began, far fewer ordinary people would have frozen to death in the short term.
But doing so would have played directly into Kali's trap.
In simple terms, Kali had forced humanity to choose between two disasters.
Freeze to death in the Ice Calamity.
Or drown in the Flood Calamity.
By now, the Newborn World Serpent had made its choice.
Even with Pardo, now an "Emanator," secretly helping people within the limits established by Ling Ke, hundreds of millions of ordinary people had still died in the frozen world.
But because the Ice Calamity had now spread almost completely, while still remaining short of a truly irreversible state…
"Even if the Super Thermobaric Bombs at the North and South Poles detonate and damage portions of the atmosphere, flooding will no longer be our greatest concern."
"The high-latitude regions have already been evacuated."
"And as the resulting tsunamis travel outward, they will gradually freeze."
The Newborn World Serpent had prepared for this.
And it had already accepted the necessary sacrifices.
Unfortunately, those sacrifices were once again the same people who held the least power and had no voice in the decision.
Ordinary civilians.
People who did not even understand what was happening.
But now…
"Let's turn your own scheme against you."
MEI's eyes sharpened.
"And use it to 'warm up' the Earth."
At that moment, the Girl Dolls began deploying in massive numbers.
With MEI's assistance, they reached the frozen ocean surfaces above the locations of the Undersea Temples one after another.
Within seconds, each unit had locked onto its assigned target.
Over the course of those brief tens of seconds, MEI had used the Key of Blankness to temporarily assume the Authority of the Herrscher of the Void.
Combined with the Power of Erudition, she opened one spatial gate after another.
And with the flawless coordination of Prometheus's self-destruct force, the efficiency of the entire deployment bordered on terrifying.
Prometheus Prime, despite carrying the Void Archives, never even had the chance to assist through the slow-activating Mimicry of the Cosmic Juggernaut.
MEI alone was enough.
By combining the full Power of Erudition with the Authority of the Void…
She had transported more than three thousand Girl Dolls to their designated locations in an almost impossibly short span of time.
As the final wave of portals closed…
"Haaah…"
MEI released a long breath.
Her body swayed slightly.
For a moment, she nearly lost her balance.
It was well known that one of the major differences between a Herrscher and a Divine Key wielder was that a true Herrscher could continuously replenish their Honkai Energy through Imaginary Space.
MEI could now do the same.
Her Honkai Energy reserves constantly recovered.
Her body and mind, however, did not.
The strain remained.
Fortunately, the first phase of the operation was complete.
Next…
"Operation, commence!" ×3000+
Across the world, the first wave of Girl Dolls began moving simultaneously.
Each possessed power approaching that of an ordinary Herrscher.
They shattered through the frozen ocean surface.
And plunged straight into the depths below.