"Woo——!"
This was the sound of a steam whistle.
A very long steam whistle.
It came from a yacht, about four hundred feet long, sailing leisurely on the sea, commonly known as a giant ocean liner.
The yacht was very grand and luxurious, far surpassing ordinary luxury liners in both scale and appearance. It looked like a palace, resplendent and magnificent, making it hard to imagine that such luxury items existed in the world.
Even more unimaginable was that such a luxurious yacht belonged to only one person.
That is to say, it was a personal property, an extremely luxurious castle built solely for one person.
Its name was——"Oceanus Grave."
And its owner was the Duke of Warlord Dominion, Dimitrie Vatler.
"I didn't expect that I would return to this island in just a few months. This is what they call the unpredictability of life, isn't it?"
At this moment, Vatler stood at the bow of the yacht, facing the wind, his gaze looking into the distance.
There, a huge artificial island was situated.
It was Itogami Island.
After several months, Vatler returned to this island.
However, the last time Vatler landed on the artificial island was for the "Blazing Banquet" and was illegal. This time, he came in the form of an official visit, openly riding his proud luxury yacht.
For Itogami Island, the current Vatler was equivalent to an ambassador from the Night Empire.
Of course, Vatler's visit had not been officially announced yet because the written application had not been approved.
However, for this vampire nobleman who had devoured two third-generations and was claimed to be the closest to the primogenitor, this was naturally not an obstacle.
"If it's not approved, then I'll just come without an invitation. That seems interesting as well."
Vatler smiled as he said this dangerous statement.
This statement smoothly elicited a response from others.
"Please refrain from making such distressing remarks on your own, Duke Vatler."
Said a girl who appeared behind Vatler at some point.
She was an extremely young girl from the Far East.
The girl had a slender figure and a face exuding a charming and elegant atmosphere. Her skin was fair, her hair color pale, reminiscent of blooming cherry blossoms. Her chestnut-colored hair was tied into a long ponytail, swaying gently in the sea breeze.
The girl was wearing the uniform of a prestigious girls' school in the Kansai region.
And in her right hand, she held a black instrument case resembling a keyboard.
"It's you?"
Vatler didn't turn around, still gazing at the artificial island ahead.
"Yes," the girl said expressionlessly, in a conventional manner. "Did I hear your excellency making dangerous remarks, or was it just my imagination?"
"Of course," Vatler replied with an elegant smile. "Regardless, I don't plan to do anything before the written response comes. It would be too rude to the object I'm about to visit, wouldn't it?"
"In other words, once the written response comes, Your Excellency plans to act accordingly?" The girl's face tightened. "Isn't that quite disrespectful to the Japanese government?"
"We'll see how the Japanese government responds in writing." Vatler glanced at the girl and smiled. "So? Did you bring the response?"
"...Yes." The girl remained silent for a moment, then sighed as if resigned. "From today onwards, Your Excellency is allowed to visit the Demon Sanctuary of Itogami Island. According to the 'Sanctuary Treaty,' Your Excellency will be regarded as a diplomatic envoy from the Warlord Dominion. This is the response from the Japanese government."
Upon hearing this, Vatler shrugged.
"It's hard to decide whether to be regretful or relieved."
Vatler's words sounded completely serious, without a hint of jest.
This made the girl's expression tighten even more, as if she dared not be careless.
"During this period, I will accompany you as your monitor."
The girl expressed as such.
"A monitor?"
This made Vatler smile somewhat pleasantly.
"In other words, once I am perceived as a threat, as a monitor, you will immediately eliminate me?"
This statement, if known by someone aware of Vatler's identity, would surely provoke laughter.
As the entity closest to the primogenitor, with Vatler's power, he could sink the entire Itogami Island. Only a primogenitor-level being could pose a life-threatening threat to him.
In such a situation, a mere human claiming to want to eliminate him?
It's simply laughable.
But the girl spoke as if it were a matter of course.
"If necessary."
The girl made such a declaration.
Instead of angering Vatler, it seemed to brighten his mood as he turned for the first time to look at the girl.
"Well, that's something to look forward to."
Vatler said so, genuinely smiling.
It's clear that this vampire noble hopes someone will come to kill him.
No, more accurately, he hopes for someone to engage him in a thrilling battle.
It was just nearly half a year ago that this lord of the Ardeal principality was defeated by Zaharias with the Matrices of six Kaleid Bloods, yet he appears lively and anticipates further combat.
Of course...
"I'm more interested in that 'Divine Child of Origin' than you."
Vatler spoke as if recalling something even more delightful.
"Even I was defeated by the six Beast Vassals of the Fourth Primogenitor, but that child was able to seal the original, which possesses nine Beast Vassals, within his own body. Interesting, truly interesting."
For this reason, Rozen has returned to this island.
"I hope that you can satisfy me."
"The 'Divine Child of Origin.'"
As he watched Itogami Island approach closer and closer, Vatler's eyes and face were filled with anticipation.
Completely unaware, the girl gritted her teeth behind him.
"The 'Divine Child of Origin'..."
In a low murmur, both hostility and killing intent permeated.
So, the luxurious cruise ship carrying the Warlord Dominion and its observer continued to sail.
Closer and closer towards Itogami Island.
Meanwhile, another ship is approaching Itogami Island.
It is a flying armored ship sailing above the sky at an altitude of one thousand meters, over one hundred and seventy meters in length, covered in a special alloy shell, equipped with four turbo engines, and twelve mechanized cannons.
On the stabilizer wing of the flying ship is the emblem of a Valkyrie wielding a large sword.
And aboard the flying ship is a knight order.
"We're almost at Itogami Island."
The leader of the knight order stands on the deck, gazing down at the artificial island on the ocean below.
"Hope everything goes smoothly."
Recalling the mission of their journey, the leader prays thus.
However, it's a futile hope.
Because...
"Something's wrong, Captain!"
A member of the knight order rushes in, flustered.
"The princess is missing!"
Just a simple sentence, yet it changes the captain's complexion drastically.
A new turmoil begins, unfolding its prologue.
And its stage is just one.
————Itogami Island.