"Boom!"
It was the sound of the city walls collapsing.
Under the relentless burning of the black mud that surged like a black tide, one of Uruk's walls gave way, allowing torrents of mud to flood into the city.
The black mud crept along the streets, only to be stopped by barriers that had been erected across the avenues at some unknown time.
This, of course, was Gilgamesh's doing.
Knowing that Uruk would inevitably be breached, Gilgamesh had made thorough preparations in advance.
After the evacuation of the citizens, he opened the treasury, bringing forth countless Noble Phantasms to serve as barriers, halting the advance of the black mud.
Otherwise, if all of Uruk were swallowed into a sea of mud, then not only humanity but even the Servants themselves would find it troublesome—unable to fight freely at all.
Now, Uruk had become a battlefield, with countless Laḫmu and myriad other creatures locked in frenzied combat.
Of them all, the clash atop the Divine Tower was the most violent, with explosions and thunderous crashes rocking the skies, the spectacle overwhelming.
"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa—!!"
Amidst this chaos, Tiamat finally arrived, standing before Uruk.
At the sight, Rozen drew a deep breath upon the wall.
"Altera!"
Without hesitation, Rozen called upon his strongest familiar and Servant.
"Hum!"
Waves of mist rippled as space itself quivered, and within the distortions a white figure emerged.
The white-haired maiden lifted her gaze toward Tiamat as she descended from midair—falling directly into the surging black sea.
"Boom!"
In an instant, the black sea roared and heaved, the mud splashing upward like black spray as though a massive stone had been dropped into its depths.
Altera landed in the sea of mud, overturning everything around her.
Then, as the surrounding mud surged forward, it all evaporated the instant it drew near.
In that moment, around Altera's body, waves of destructive energy surged—like a dark phosphorescence rippling outward.
Under this destructive energy, every touch of mud was burned away, scorched into nothingness.
Altera stood unyielding in the black sea, her ruby-like eyes fixed on Tiamat.
That single gaze was enough to halt Tiamat's advance.
"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa—!!"
With that cry, Tiamat's eyes, as they met Altera's, revealed astonishment, rage, and even fear.
The Creator Goddess had recognized Altera's identity.
Altera gazed back at Tiamat and spoke softly.
"Looking at you… is like looking at my past self."
It was a truth straight from her heart.
In ages long past, Altera too had become an invincible giant god, rampaging across the earth—destroying, annihilating, devouring everything before her.
It was then that the Age of Gods truly began its decline. Countless deities weakened.
And the prehistoric civilization was utterly destroyed, wiped away without a trace. Humanity would not flourish again until ten thousand years later, with the rise of the four great ancient civilizations, led by Sumer.
That was the legacy Altera had once forged with her own hands.
If not for her body's eventual sealing and her avatar's death, this planet might well have become nothing but a dead star beneath her.
At the thought, even Altera's voice wavered slightly with emotion.
"I know… I have no right to stop you, no right to stand before you as humanity's shield."
She had once done the same, and worse. What right did she have to oppose Tiamat now?
And yet—
"Even so, I have something I must do. I cannot allow you to succeed."
Even without qualification.
Even without reason.
Altera's purpose had never changed.
She would be Rozen's weapon.
Therefore—
"This civilization—I will not let you destroy it."
Thus declared the invader of planetary civilization.
"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa—!!"
Tiamat roared, enraged, and the black sea churned violently, rising as a massive tsunami surging toward Altera.
"Destroy!"
Altera raised the Sword of Mars high, destructive energy bursting forth as radiant streams of light, then brought it down in a mighty slash.
"Boom—!!"
The destructive light swept upward from the ground, vaporizing the black mud, tearing apart the oncoming tsunami, like an immense arc of swordlight cleaving downward into Tiamat.
"Shhhhk!"
Tiamat, whose body was nigh impervious, her Saint Graph so solid it could scarcely be shaken, let alone injured—was sliced open under the weight of that colossal blade of light.
"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa—!!"
A cry of pain rang from Tiamat's throat at last.
From the wall, Rozen saw it happen—and in the next moment, a report came through the communicator from Chaldea.
"Confirmed—Beast II's Saint Graph structure has taken damage!"
"Saint Graph values fluctuating! A definite decrease detected!"
"It's working! Altera's attacks are effective against Tiamat!"
Roman, Da Vinci, and Olga Marie's voices overlapped, both nervous and elated, as Rozen's spirits lifted.
"Good!"
That was all he needed.
As long as it was effective, Tiamat's Saint Graph could truly be weakened, the operation progressing toward success.
Though Rozen's own Wise Eye and Mind's Eye told him the damage dealt had not even reached one-thousandth of Tiamat's Saint Graph, and though Altera's power was greatly diminished by manifesting under the limits of a Servant, unable to unleash her true might—even so, Rozen himself could not have done any better.
Altera's strength was the natural counter to Tiamat. Truly, she was worthy of the title "Rozen's trump card."
But recognizing Altera's danger, Tiamat exploded with fury.
"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa—!!"
She stirred the black sea around her, while raising her colossal hand to strike at Altera.
That claw descended like a meteor crashing from the heavens, igniting the atmosphere as it fell, fire scattering, turbulence shaking the skies.
At this, Rozen knew he could hold nothing back.
"Lend me your strength!"
Rozen shouted aloud.
"Mesarthim Adamas!"
"Cor Tauri Succinum!"
"Al Meissa Mercury!"
"Natra Cinereus!"
"Regulus Aurum!"
"Minelauva Iris!"
"Kiffa Ater!"
"Shaula Viola!"
"Alnasl Minium!"
"Dabih Kryastalos!"
"Sadalmelik Albus!"
"Alrescha Glacies!"
As mana surged violently, the twelve Beast Vassals—once hailed in another world as natural disasters, as the strongest familiars of the Fourth True Ancestor—were summoned forth together in a single breath.
Twelve colossal Beast Vassals appeared in the skies, each letting out earth-shaking roars as they charged straight toward Tiamat.
The world quaked with their thunder.
The great battle had begun.