"According to Yukari's intel, the Divine Child has already departed from Itogami Island and is heading here at incredible speed. It shouldn't take long for him to arrive," Shirona reported calmly.
"That boy managed to seal the Fourth Primogenitor and maintains deep connections with the gods. Yukari also mentioned he seems to have resolved the Original sealed within him. While the exact details still need verification from Shizuka, one thing is certain - beings like the Fourth Primogenitor no longer pose any threat to him."
Though some aspects remained unclear, one fact was undeniable:
"When the Divine Child arrives, he might be able to resolve the Holy Annihilation legacy in the lake in one fell swoop," Shirona suggested to Hisano.
"...Is that so?" Hisano's expression darkened. "That might be good news for us, but can we afford to wait?"
Shirona answered decisively: "Probably not."
"The Self-Defense Forces report the spiritual entity at the lake bottom has been continuously activating. The pressure has increased by 1.25% in the last 48 hours, with magical energy concentration reaching 774 times baseline levels - well into the danger zone."
"Has it come to this already?" Hisano murmured.
"Indeed," Shirona nodded. "Calculations show if this trend continues, the local ecosystem will soon suffer severe impacts. Worst case scenario - within days, the surrounding urban areas could vanish without trace, just like that village forty years ago."
The two girls at the door paled at this revelation, while Hisano sighed as if expecting this outcome.
"Then we cannot wait for the Divine Child's arrival. We must resolve this before that happens," Hisano declared with resolve.
"Decision made then?" Shirona asked, her tone hovering between approval and testing. "But this means your precious granddaughter may be put in danger. Are you truly alright with that?"
"The Lion King Agency has promised her protection, hasn't they?" Hisano countered calmly. "Moreover, since ancient times, whenever the 'Horned Serpent' shows signs of awakening, the Shinokuda Shrine has always suppressed it. As my granddaughter, it's time Nagisa fulfilled this duty."
"Horned Serpent...?" Shirona murmured. "That's what you call the sealed entity?"
"Unclear," Hisano shook her head. "But ancient texts describe it as 'the Horned Serpent - harbinger of calamity.'"
Thus, the shrine maidens tasked with suppressing the disaster in Shinjin Lake had always referred to it as the Horned Serpent.
"For generations, our shrine has guarded this place to suppress the Horned Serpent. To strengthen the lake's seal, several shrine maidens have sacrificed themselves," Hisano explained gravely.
"They offered themselves as living sacrifices to the lake, continuously reinforcing the seal through the ages."
Now with the seal weakening again and the Horned Serpent nearing release, the shrine could no longer remain passive.
Traditionally, as head priestess, Hisano should be the one to sacrifice herself to reinforce the seal. But her advanced age and diminished spiritual power meant this duty would fall to another.
Under normal succession, this responsibility would inevitably fall to Nagisa as Hisano's granddaughter.
In other words, in the past, Nagisa would have been required to sacrifice herself to strengthen the lake's seal.
With her exceptional spiritual medium capabilities and status as a Hyper Adapter, her sacrifice could maintain the seal for another century.
But Avrora's appearance provided an alternative.
"Avrora Florestina is inherently a sealing vessel. If we use Nagisa's abilities to spiritually synchronize with her and acquire those properties, then through ritual transfer Nagisa's spiritual power to the lake, we could strengthen the seal without requiring a sacrifice," Shirona outlined their plan.
"Provided Nagisa's spiritual power can successfully acquire Avrora's properties as a sealing vessel," Hisano pointed out the plan's uncertainty.
While success would mean a perfect resolution, if Nagisa's abilities proved insufficient to deeply connect with Avrora's spirit and imprint those sealing properties, the ritual would fail.
Moreover, Nagisa's spiritual abilities were damaged during the Blazing Banquet. Even with signs of recovery after Rozen sealed the Original, it remained unknown if she could return to full strength. Even at her peak, success wasn't guaranteed - current estimates gave the ritual less than 50% chance of success.
Should they fail...
"Then we must immediately attempt the alternative ritual - transferring the Holy Annihilation legacy from Shinjin Lake into Avrora Florestina, having her serve as the sealing vessel," Shirona revealed their contingency.
"In that case, Avrora might fall into deep sleep like before to strengthen the seal, possibly never to wake again," Hisano voiced her concerns.
"Then we simply have the Divine Child intervene. That was always part of our plan, wasn't it?" Shirona dismissed lightly.
The Lion King Agency had prepared two approaches - one centered on Nagisa, the other on Avrora. The former was safer but less likely to succeed; the latter more dangerous with greater consequences for Avrora.
If forced to use Avrora as the seal, the Agency planned to return her to Rozen once he arrived.
Given Rozen's proven ability to seal the Original and even summon gods, they believed he could resolve Avrora's sealed state.
Of course, the Lion King Agency would then face Rozen's wrath.
But they had no better options.
The alternative - having Nagisa sacrifice herself as a shrine maiden - would be completely unacceptable to Rozen.
Thus, the Agency could only choose the lesser of two evils.
"Let's begin preparations immediately," Shirona declared.
"Agreed," Hisano nodded solemnly.