Was Arcueid provoked by something?
Guinevere, who had some recollection of Tsukihime and knew that Kirei Kotomine had obtained the True Ancestor's blood from Ciel's body, quickly put the pieces together. She pressed her hand against Caren's back.
Before she could do more, Shiki Tohno lunged forward as if he'd lost his mind. He had seen it—the exceptionally faint death line over Caren's heart was already extending, spreading.
Any later, and the little brat would have been turned into a Dead Apostle.
But Gareth, at his side, tackled him around the waist, holding him fast. The King of Knights knocked the small knife from his hand. Morgan forced the Mystic Eye Killers back onto his eyes and blasted him in the face with a water ball.
In that instant, he snapped back to his senses.
In that same instant, Guinevere thrust her hand through Caren's chest, ripping out her heart—a heart completely saturated with the blood of the True Ancestor, Roa.
"Second Noble Phantasm activated! Caren, your body is unharmed!"
In Guinevere's blood-soaked hand, Caren's original heart still beat vigorously. Meanwhile, a new, false heart had already formed in her chest cavity, and even the wound on her body had vanished.
But while her body was outwardly healed, the pain she had endured was real. Caren's body convulsed in agony, unable to utter a single word.
"Sister Morgan!"
With Caren's heart removed, the coffin sealing Arcueid began to shake even more violently. The agitation Shiki Tohno had just suppressed surged within him again.
It wasn't until Morgan took the heart and sealed it, preventing its aura from leaking out, that the commotion subsided.
"This heart indeed contains True Ancestor blood," Morgan said. "Also, do you remember? The Blood Poison the Holy Church unleashed on Camelot City used blood from the same source as this heart. Heh, I've studied it occasionally over the past thousand years. I never thought I'd actually get to use my research."
Even Morgan, despite 1,500 years of continuous research, hadn't found a way to completely neutralize or annihilate the True Ancestor's blood. Her research focused on suppressing it and then surgically removing it.
Of course, she offered no guarantee that the subject would survive the removal of the True Ancestor's blood.
And...
"Guinevere," Morgan said, "do you want to hunt down the True Ancestor himself? With blood of this purity, I can use it as bait to lure him out."
The coffin thrashed again, but this time, the movements became rhythmic. A broken voice emerged, speaking in disjointed fragments.
"Take... me... Find... Roa... Kill... kill him!! ARRRRRRRRR..."
The brief moment of coherence quickly devolved back into utter madness. Morgan attempted Hypnosis Magecraft, but it had little effect. As the coffin began to crack under the relentless assault, Shiki Tohno was ordered to use a similar Command Spell.
"Berserker, by my Command Spell, I order you to sleep quietly!"
Shiki had already used one Command Spell when summoning Arcueid, but since the order was simply to "behave," it had been almost completely ineffective.
This time, the order was simply to sleep, and the Command Spell's compulsion managed to have some effect. In coordination with Morgan, it finally quieted her temporarily.
Sighing in relief, they exchanged glances. Arcueid was undoubtedly a powerful Servant, but once she lost her sanity, she became an extraordinary hassle.
"Tohno-kun," Guinevere said, "you summoned her, so you're responsible for her."
"Big Sister Guinevere, how am I supposed to do that?"
"By taking your Servant to kill Roa, of course. Go and personally quell the turmoil in both your bloodlines. Sister Morgan, I'll leave this heart with you to turn into bait for him. And give Tohno-kun a copy of your research from all these years."
"You really believe they can kill the True Ancestor himself?" Morgan asked. "If they kill him now, won't his will just revive in Kirei Kotomine?"
Michael Roa Valdamjong, known as the Serpent of Akasha, was a former priest of the Church and the original founder of the Burial Agency. Centuries ago, he tricked the Dead Apostle Princess—Arcueid—into drinking his blood. This completed his reincarnation technique, allowing him to achieve eternal life through endless rebirths.
However, after drinking his blood, Arcueid went mad. She not only slaughtered the other True Ancestors in her home, Millennium Castle, but also spent the next several hundred years relentlessly hunting Roa in a state of insanity.
The Berserker-class Arcueid that Shiki Tohno had summoned by chance was likely the version of her from that very period.
Only the Throne of Heroes, where past, present, and future exist simultaneously and which stands outside the timelines of countless parallel worlds, could allow a specific aspect of this Vampire Princess to be summoned as a Servant from a certain period, even while she is still alive and wandering somewhere unknown.
"Sister Morgan, just do as I say and leave this to them," Guinevere urged. "Just pretend I can still see the future, alright? Besides, they can go on a trip, but what would it look like if we ran away from this Great Holy Grail War?"
Morgan was convinced. After all, their true enemies were the bastards who had died long ago and the Holy Church from the Camelot era. Back then, Roa's blood was merely a tool. Now, with the Purification Plan in effect, their grudge was at most with a faction within the Holy Church, not the entire organization.
"Fine," Morgan conceded. "I'll leave it to them."
As she spoke, she tossed several vials and jars into Shiki Tohno's hands. She then inscribed Caren's still-beating heart with Magecraft runes before sealing it inside a small box.
"Here," she said. "You have until the end of the Great Holy Grail War. If you can kill Roa sooner, come back as soon as you're done."
With the necessary items and instructions delivered, Shiki Tohno wasted no time. He hoisted the coffin onto his back and prepared to leave, only for Morgan to present him with another new item: a homunculus girl the King of Knights had picked up along the way.
In the field of homunculi, Morgan had created Mordred, as well as Mordred's failed siblings—brothers and sisters forged after Mordred's ascension to the throne.
Since then, Morgan had delved even deeper into homunculus research. In terms of sheer skill, even the Einzbern Family would have to kneel before her.
As a result, the Yggdmillennia homunculi she modified would gain longer lifespans, absolute loyalty to her, and bodies born for combat—making them perfectly suited to carry Shiki Tohno's coffin.
Of course, they also served as Morgan's eyes and ears among them.
After Shiki Tohno's group departed, the short, stout Gordes approached Morgan with a fawning expression. To him, if he could obtain Morgan's superior homunculus technology, why would he bother seeking the Einzberns' inferior version?
"You want it? Very well, you may have it. But I will only give you the initial version. That is all Guinevere's promise is worth!"
"That's more than enough! More than enough! I, Gordes, and my future children—we will forever remember the Pendragon lineage's kindness!"
With that, the short, stout Gordes also left. Having lost his Servant but gained what he truly desired, he had no intention of ever returning to the Yggdmillennia Family.
Guinevere understood, however. While Yggdmillennia called itself a family, it was actually a Mage Association composed of failed mages. Upon joining, members were simply required to adopt the Yggdmillennia family name.
But at this point, in the current stage of the war, Guinevere had one less Master-Servant pair she could command. The conflict had truly become a direct confrontation between her Pendragon lineage and the Yggdmillennia lineage.