Mass refers to the inherent physical quantity possessed by matter.
According to the theory of relativity, it fundamentally represents a value indicating 'the degree to which matter is difficult to move.' Depending on how it acts, it is categorized into inertial mass, active gravitational mass, and rest mass.
Among those, gravitational mass—what we commonly refer to as weight—changes according to gravity.
Naturally, an object falls due to gravity, and its destructive force increases, becoming gradually amplified by acceleration.
Just as even the most powerful magus would have their head pierced by a Magnum bullet, even the mighty evil dragon Fafnir could not remain unscathed after being struck by a blow that dropped boulders the size of its own skull from outer space. This is doubly true when that object is saturated with Mystery.
"...Phew, this is exhausting."
Following a string of battles, the decoy operation with Marie. The traps laid using Command Spells, sniping the Berserked Servants, the deployment of the Asura Path... and the decisive strike, Tengai Shinsei—Heavenly Obstruction: Shattering Star.
My magical energy was hitting rock bottom due to the constant combat. I began to use Preta Path: Seal Absorption to slowly stabilize my creaking Magic Circuits.
"Even if Ritsuka avoided it using Emergency Evasion... you're still alive after being hit by a meteor? You certainly are persistent, Gilles de Rais."
"Vengeance... I must see my vengeance through! I, Gilles de Rais, shall have the Holy Maiden's revenge!!! We will satisfy our resentment!"
"Yes, Gilles. We must surely pay them back. Do not stand in our way, Master of Chaldea!!!"
Right, it seems we have to see this through to the bitter end.
After all, there's nothing more tiresome than dealing with those bound by the category of 'Vengeance.'
"Come forth, my summons! Manifest your hidden strength here and now, and tear the Master of Chaldea limb from limb! Bring your power into existence upon this ground!"
Whether he had completely given up on Fafnir's recovery or not, Gilles de Rais began to concentrate the magical energy of the Holy Grail into his Noble Phantasm.
Dozens of writhing tentacles began to crawl out from the book made of human skin, to which the face of a young child was still attached. They soon took form, beginning to shape into a 'mass' as immense as one of Fafnir's legs.
"Fall into madness! Behold the insanity! Forget yourselves and sink into nothing but the pleasure of retribution! We raise the flag of vengeance once more! Gather, you forsaken ones; gather, you persecuted ones! The Dragon Witch leads us, and I shall rule! The resentment of us, the oppressed, shall surely reach God himself! Oh, you foolish ones who deem yourselves righteous, I offer my body to denounce you! You arrogant, cold-blooded wretches! We shall drag you down from your thrones!"
"Denouncing us? Don't make me laugh, Gilles de Rais! What kind of retribution can a man who is committing such follies in the name of 'helping' Jeanne d'Arc even talk about!"
Before I knew it, the battle was entering its final stage.
Gareth was working with Jeanne to corner Jeanne d'Arc Alter, while Ritsuka was being supported by Mash, supplying her with magical energy.
"Do not listen, Jeanne!! My Saint! Even without Fafnir, even if the Berserked Servants vanish!! This unworthy Gilles de Rais shall serve by your side until the very end!"
"Cut the bullshit. The witch next to you is nothing more than a doll you manufactured with the Holy Grail! If you wanted her so badly, you should have just prayed to the God in the heavens! You should have asked to bring the Holy Maiden back to life exactly as she was!"
"Silence, you! Do you intend to insult my Saint to the very end!"
"You're the one insulting her! Who is it that received a pathetic Grail and turned the world she saved into a living hell, driving the humanity she protected toward ruin? Who is it that burned down her family and her hometown, and tortured and killed her comrades!!! You aren't the Holy Maiden's lieutenant, nor are you a proper Avenger. You're nothing more than a mad dog destined to die after running wild in your own delusions!"
They say that when a human has nothing left to say, they resort to insults.
Whether Gilles de Rais truly ran out of words or simply wanted to kill me as quickly as possible, he began to focus solely on gathering magical energy.
...And I was the same.
My magical energy was depleted, but I always leave enough to use my abilities.
I summoned the Asura Path, which effectively serves as my substitute for Gilgamesh's Gate of Babylon, and pulled out a small flask from within.
Normally, I would have to summon this in an indoor setting like an amusement park or a hotel, but in any case, this site had become a sealed chamber of sorts due to the piles of debris left by the meteor.
"Did you think I would let you pull any more tricks!!"
Two tentacles flew out and pierced my body.
When my heart area was accurately pierced, Gilles de Rais quickly retracted the tentacles, snatched my face in a rough grip, and slammed me into the ground.
As expected of a Servant... even in the Caster class, they are anything but ordinary.
"...If that were actually me, that is!"
"Don't tell me, you again...!"
With high-intensity Sun Runes etched all over my body and the stasis-type Noble Color Mystic Eyes Ritsuka possessed... no matter if they were a Servant, the Mystic Eye abilities amplified by the Mystic Eye Railgun would take effect. This was especially true for a Caster who lacked Magic Resistance.
"I know everything about your Noble Phantasm. It's possible to summon familiars and hide within them... but they are creatures that act of their own accord in the end, aren't they? Of course, simple manipulation is possible... but because of that, there's even less worry of you escaping."
All the conditions were met.
There was no one to interfere, and the debris satisfied the condition of a labyrinth or an interior room... All that remained was the ritual.
Crossing my fingers like a shadow and letting a single drop of blood flow over them concluded the process.
"Witch of Fairy Tales—Oil of the Forest God—Night of Phantasmagoria—I manifest the demonic mirror that leads the foolish."
A skull-shaped moon rose in the sky, and the surrounding environment began to transform into a charming fairy tale.
The Noble Phantasms held by the Servants retained their magical energy, but their appearances changed into toy swords one might see in a storybook. My own attire also transformed from a Mystic Code emphasizing practicality or the karmic burden of life into a dapper, formal party suit.
And most decisively, the transformation of the horrors Gilles de Rais had summoned.
"How can the demonic beasts summoned by my Noble Phantasm...!"
"...Like I said, you aren't a proper Caster."
The most basic rule of all magecraft.
When a Mystery collides with a more ancient Mystery, it collapses or vanishes.
Gilles de Rais's friend, Francesca Prelati, is a literal monster who has survived since the age of King Arthur, but the 'history' of Prelati's Spellbook effectively stopped the moment she handed it to Gilles.
On the other hand, the Flat Snark of the previous Meinster, who lived in the same era as Francesca, has continued to live into the current age as one of the 'Great Three,' continuously accumulating its level of Mystery.
"The power itself might be similar. Perhaps yours is even higher since it's a Noble Phantasm... but that is only the Mystery of your 'Noble Phantasm' itself."
Those summons, however, are another story entirely.
"Gugh... kakh, hack... Jeanne! My Holy Maiden, please strike them down!!!"
Gilles de Rais tried to resist by pulling out the Holy Grail, but the tentacles, which were now completely obeying my command, instead coiled around Gilles and began to tighten their grip on his body.
Jeanne d'Arc Alter tried to approach to help him, but Gareth caught an opening and halved her side with a strike, causing her to collapse.
"No, we can't be defeated like this...!"
"Mister! How long can you maintain that technique!"
"As long as necessary. Still, it would be best to kill him right now."
Giving Ritsuka some light advice, she cupped her hands around her mouth and shouted while clinging to Mash's shoulder.
"Siegfried, fire Balmung! Send that Fafnir back for good!"
"Okay, then we should make our escape too. We've got the Holy Grail, so there's no reason to stay here!"
Gareth jumped down first, and I summoned a Nue to evacuate into the air.
A moment later, a massive flash of True Ether enveloped Fafnir. The evil dragon, still maintaining its gargantuan frame, was reduced to golden particles and oxidized into nothingness.
...Along with a miserable madman who spewed curses until the very end.