I had miscalculated.
"As expected, I should kill you another hundred times."
Kei said with obvious dissatisfaction,
"What made you think I could summon Divi:Sion in a place like this?"
That meant my hopes of resorting to overwhelming numbers had officially gone up in smoke. She could do it in the Slumpia, so why not in these catacombs?
"...Because over there, there happened to be an enormous amount of resources that I could freely control, and the terrain was simple enough."
She looked at me with her cold pinkish-purple eyes.
"Are you asking that on purpose? Or have you forgotten even this much basic common sense?"
Common sense according to whom?
The Nameless Gods?
There was probably no one else in all of Kivotos who understood the ecology of the Divi:Sion as well as she did.
In any case, thanks to Mika sacrificing herself to draw away the majority of the enemy forces, the rest of our journey could only be described as cutting through everything in our path.
The four girls who now belonged, or had once belonged, to Arius Squad had all undergone brutal training. They were battle-hardened, strong-willed, and still in excellent condition. Even Saori, whom Mika had nearly beaten into a critical state, had recovered after drinking my holy blood.
As for Kei, although she couldn't summon Divi:Sion and insisted on letting me keep the Sword of Light for self-defense, the physical abilities of Arisu's body far surpassed everyone else present. She could even snap the marble pillars lining the passage with her bare hands, just like Mika.
As a result, even empty-handed, Kei could easily deal with several ordinary Justina Council soldiers simply by relying on that body of steel.
Unfortunately, that rare feeling of smooth progress did not last long.
"...Is the place you're heading to just ahead?"
After defeating a humanoid aberration over twice the height of a normal person, Kei suddenly stopped and asked us with a solemn expression.
"Yes."
Saori nodded.
"Just ahead should be the Sanctum of the Basilica. Is something wrong?"
"I won't be going any farther."
After a brief pause, Kei explained,
"The area ahead carries the presence of some kind of dangerous ritual currently being performed. Arisu and I cannot recklessly approach it. As the Key for Princess of the Nameless Gods, if I interfere in a ritual whose purpose is unknown, it could easily trigger severe and unpredictable consequences. So this is as far as I can go."
What an incredibly troublesome setting, in every possible sense.
Still, I more or less understood.
In other words, she simply couldn't go any farther.
"...I understand."
After a moment's pause, I spoke sincerely.
"Thank you, Kei."
Even if I wasn't prepared to truly forgive her, I was willing to thank her for everything she'd done to help us get this far.
"...The one you should really thank is Arisu."
Kei turned her back to us, her voice remarkably calm.
"You're going to keep going, aren't you?"
"Of course."
I answered without hesitation.
"I see."
She gave a small nod.
"Then I'll go support the pink-haired girl who lured away the replicas."
The next moment, she ran back the way we had come, empty-handed.
Watching Kei rapidly disappear into the distance, I withdrew the gaze I'd been about to use to stop her and return the Sword of Light, along with the question I'd intended to ask.
Instead, I continued forward with the others, lost in thought.
How should I put it...
After seeing her performance in battle, I now had a clear understanding of Kei's strength.
At the same time, considering how cunning she was, I should probably trust that she wouldn't recklessly do anything dangerous with Arisu's body...
Honestly, even now, it still felt rather unbelievable.
Fighting alongside someone who had genuinely wanted to take my life left me with very mixed feelings.
I couldn't help muttering quietly,
"Maybe my wonderful personal virtues are just so noble that they can even reform a rogue AI who treats human lives like dirt."
"Wow, Sensei is amazing!"
Arona exclaimed admiringly before asking eagerly,
"Then that means the Decagrammaton and the Prophets can be reformed too, right?"
In Arona's mind, was I the sort of person who accepted every bizarre thing under the sun?
At the very least, they'd have to look like cute girls.
Pretending to talk to myself so the others wouldn't notice, I used the lighthearted banter to ease my increasingly tense nerves.
Passing through a heavy curtain, what greeted us was a dilapidated ancient church.
Many of its decorative pillars were cracked and broken. The marble walls on both sides were inlaid with stained-glass windows, most depicting rays of light descending from the heavens, but they too were shattered, with pieces missing everywhere.
At the center of the church stood a stone platform shaped like an eight-pointed star.
Upon it, a purple-haired girl was bound in place by crimson thorn-like vines.
Even though she wore a mask, I recognized Atsuko immediately.
Behind her, the stained glass depicted a grotesque scene disturbing enough to provoke a physical sense of revulsion.
Its body was unnaturally slender.
Its enormous claws were skeletal and sharply jointed.
Behind its shoulder blades grew a pair of superfluous limbs resembling bony wings.
Its lower body stretched out like a tree trunk and roots, merging into branching forms like the limbs of a great tree.
Most striking of all was its head.
It consisted of more than a dozen white wings arranged like the petals of a blooming flower, each embedded with a black eye bearing a crimson iris.
I had only seen similar features on one other being.
Was this...
...the form Beatrice longed to become?
Such a hideous monstrosity suited her equally hideous soul perfectly.
"Princess!"
Saori cried out anxiously.
But there was no response.
Looking more closely, even Atsuko's halo had already disappeared.
Misaki calmly assessed the situation.
"...She seems to have only lost consciousness."
"W, we have to get the Princess..."
Hiyori had just started to rush forward when the woman's voice we all despised echoed through the church, exactly as expected.
"I've been waiting for you for a long time, Sensei. I must overcome... the enemy whom I am destined to kill."
"Beatrice..."
I turned toward the source of the voice.
The woman with crimson skin, a white dress, and a face covered by white feathers stepped out from the shadows.
An unbearably smug smile hung on her face, the kind that made me want to punch it on sight.
"But it's already too late. The ritual is already underway. By extracting the Mystery of the royal bloodline, the Piercer of Destiny, and borrowing the power that came from beyond Kivotos... I shall elevate myself into a higher existence."
She stared directly at me.
"Come, Sensei. Adult whom I cannot understand, my destined adversary. Bear witness. With only this insignificant sacrifice, I shall achieve a greatness no less exalted than yours!"