Under Medea's guidance, Leo passed through a hidden stone staircase in the temple's rear courtyard, descending deep into the interior of the mountain where Ryuudou Temple stood.
This was a vast underground cavern, its scale far exceeding Leo's imagination.
The air was saturated with magical energy so dense it was nearly tangible, causing even this half-baked magus to feel waves of skin-prickling sensation.
In the center of the cavern, an enormous golden spherical object floated silently, countless intricate magical circuits flowing like golden blood vessels across its surface, forming a mysterious and magnificent tableau.
This was the true form of the Fuyuki City Holy Grail.
At this moment, it appeared sacred and solemn, bearing none of the black mud-filled, ominous appearance from the FGO game.
"There it is, maintaining the ley lines of Fuyuki City while also serving as the core of the Holy Grail War system."
Medea's voice echoed through the spacious cavern, carrying a note of gravity. "Now, I will conduct a thorough 'examination' of it."
As soon as she finished speaking, the demeanor of this Divine Age sorcerer underwent a sudden transformation.
She extended her slender fingers, tracing elegant arcs through the air.
Ancient and obscure syllables flowed from her lips—not any language used by modern magi, but rather the incantations of magic bestowed by the goddess Hecate herself in the age of mythology.
As she chanted, magnificent magical energy converged around her, transforming into countless pale purple runes that danced like a summoned swarm of butterflies.
"Go forth, seek its essence, reveal its origin."
Medea commanded softly.
The runes, as if possessed of life, surged toward the central Holy Grail, gently adhering to its golden exterior.
At first, the runes emitted a soft purple glow, and everything appeared normal. But mere seconds later, a sudden change occurred!
The runes affixed to the Holy Grail's surface, as if ink had been dropped into clear water, began to be rapidly tainted from their edges by an ominous, pitch-black color!
That blackness was filled with malice and chaos, and merely looking at it caused Leo to feel a wave of heart-palpitation.
Medea's brows furrowed tightly. She increased her magical output, sending more runes toward the Grail, attempting to penetrate its core.
Yet no matter how many pure runes adhered to it, they would be devoured and assimilated by that eerie darkness in a short time.
The entire process lasted approximately ten minutes before Medea gradually ceased her incantation, fine beads of perspiration appearing on her forehead.
"...The situation is worse than imagined."
She withdrew her magical power, her complexion somewhat pale. "Its core is indeed contaminated by an extraordinarily vast malice. Just as your intelligence stated—'All the Evil in This World'...truly an apt name. Any pure wish cast into it would be twisted into the most vicious curse."
Hearing this conclusion, Leo's heart sank, but he still pressed further: "Then...is there a way?"
"There is."
Medea's answer was decisive, her eyes brimming with the pride and confidence of a top-tier magus. "Though this contamination is malignant, its method is not beyond my comprehension. Given sufficient time and materials, I am confident I can construct a large-scale purification ritual before the ceremony's final completion, separating this contamination from the Holy Grail system."
"While I cannot completely eradicate it, I can at least ensure it becomes a properly usable, pure collection of magical energy—a functional wish-granting machine."
This promise was like a shot in the arm, allowing Leo to finally set down the heaviest stone in his heart.
As long as the Grail works!
As long as the Holy Grail functions, his wish—and the futures of those girls he had involved—would all have hope!
"That's wonderful, Caster! Thank you so much!"
"No need for thanks, Master. This is also for my own sake, to obtain a wish free from taint."
Medea smiled slightly, then changed the subject. "Now that the greatest problem has a solution, we should discuss how to obtain the souls of those seven Servants."
The two returned to the guest room, and a new round of tactical discussion began.
"Caster, since we can definitively dispel all charm effects afterward..."
Leo mused, proposing a bold idea. "Perhaps this face of mine is not entirely without use."
Medea's hand, holding her teacup, paused slightly, and she raised her eyes to look at him.
"According to my 'intelligence,' the participants in this Holy Grail War have a considerable proportion of females."
"Saber Artoria, Rider Medusa, their Masters Rin Tohsaka and Sakura Matou, and Illyasviel of Einzbern...if I could take the initiative to contact them, without arousing suspicion, perhaps I could achieve victory without bloodshed..."
He did not finish his sentence, but the meaning was clear.
This was opening Pandora's Box.
Using his most deeply despised curse as his sharpest weapon.
Medea fell silent.
She looked at Leo, her eyes complex. She understood this was the most efficient tactic, but the thought of Leo actively facing that madness again, which could twist the human heart, filled her with instinctive resistance.
"Master...I do not recommend you lightly wielding that power."
She spoke softly, her tone carrying a hint of barely perceptible concern. "It is also a form of irreversible desecration to yourself. Each use deepens your connection with this curse."
"I understand."
Leo nodded. "But if it can reduce unnecessary combat and casualties, I believe it is worth attempting."
"...Very well."
Medea ultimately relented. "I respect your resolve. We shall treat this plan as our trump card in reserve. Should the moment come when we have no other choice...I will prepare the follow-up rituals for you, ensuring you will not be backlashed."
"Thank you."
With this matter resolved, the conversation naturally turned to strengthening their own combat capabilities.
"The ley lines of Ryuudou Temple are extremely conducive to my abilities. Here, my strength far exceeds what I can display elsewhere. My only weakness is insufficient direct defensive power."
Medea gestured toward the temple's mountain gate. "That long flight of stairs is the only entrance and an excellent defensive position. According to the special rules of the Holy Grail War, I can violate the rules and summon a Servant here, making him the 'gatekeeper' guarding the mountain gate."
"Wait, Caster."
Leo immediately interrupted her, "Regarding the summoning of servants, I have some... special suggestions."
"Oh?" Medea raised an eyebrow, looking at him with interest, "Let's hear it."
"First of all, why limit ourselves to Assassin?"
Leo's eyes gleamed with the light of a gamer, "Sasaki Kojirou is certainly powerful, but he's ultimately a 'fake.' His Noble Phantasm 'Tsubame Gaeshi' is strong, but against truly powerful opponents, its effectiveness is limited."
"What I mean is, can't we choose some more... genuinely powerful combatants?"
Leo began enthusiastically introducing his vast "Heroic Spirit Compendium" to Medea.
"For the Assassin class, the most orthodox inheritor—the Old Man of the Mountain, 'Hassan of the Cursed Arm.' They're not a single individual, but successive leaders of an assassination cult bearing this name. For example, there's the 'Hundred-Faced Hassan' with splitting abilities, the 'Quiet Hassan' whose entire body is poisoned, and the 'Cursed Arm Hassan' who can extend a demonic arm to curse enemies... Each of them is a top-tier assassination expert, far more practical than a fictional swordsman."
Medea listened quietly, her expression gradually shifting from calm to astonishment. Many of the names and abilities Leo mentioned were secrets she herself had never heard of.
But Leo's "performance" was far from over.
"Moreover, Caster, your Age of Gods sorcery is so powerful—is it possible... to summon servant classes outside the normal rules?" He lowered his voice, presenting an even more tempting proposal.
"For instance, heroic spirits born from the obsession of revenge—Avenger? Or perhaps those whose nature has been inverted for certain reasons—Alter? Their combat power often far exceeds the conventional seven classes!"
"Even..."
Leo paused, voicing a thought that even he found somewhat mad, "Is it possible to directly summon a... Beast candidate?"
Boom!
The moment those final words left his mouth, the magical energy surrounding Medea trembled.
She stared at Leo as if looking at a monster.
Avenger... Alter... even Beast... These concepts had completely transcended the scope of the Holy Grail War, touching upon the realm of Counter Force and the planet itself!
What exactly did this man's "parallel world intelligence" contain?!
For the first time, Medea felt that the Master she had summoned possessed mystery and value far deeper than she had imagined.
He wasn't merely a Master with a strange curse—he himself was a massive "variable" capable of overturning the very foundations of the Holy Grail War.
She looked at Leo, and after a long moment, slowly opened her mouth, her voice carrying a tremor of excitement even she hadn't noticed.
"Master... tell me everything you know about those 'special' summoning candidates."
"Let us select the most suitable... 'gatekeeper.'"