When Shirou Emiya first walked into Kotomine Church, he thought he was going to hear an explanation of the rules. Rin Tohsaka led him through the night of Fuyuki, pushed open the heavy door, and inside awaited him a smiling priest, a standard spiel about the Holy Grail War—‘seven Servants, seven Masters, the Church as neutral overseer’—and, though he had no idea at the time, the hollow shell of a system that had been completely eaten away from within.
This is the cruelest joke of the Fifth Holy Grail War: when a new participant thinks they are ’learning the rules,’ they are actually walking right into the biggest loophole in those rules.
The Overseer on Paper: A Power Never Seriously Defined#
The oversight system of the Holy Grail War, if you scour all available sources, amounts to just a few lines. When Tokiomi Tohsaka briefed Kirei Kotomine three years before the Fourth War, he was quite clear: the Holy Grail War in Fuyuki was created by the Three Founding Families (Einzbern, Matou/Makiri, Tohsaka) to reach the Root, and the Holy Church is responsible for oversight. The overseer’s duties roughly include: maintaining the secrecy of the war (magecraft must not be exposed to the world), intervening to mediate when necessary, and providing rule explanations and sanctuary to participating Masters.
But there is a problem that was buried from day one: the boundaries of the overseer’s authority have never been clearly defined. How many Church resources can the overseer mobilize? Can the overseer themselves or their relatives participate in the war? If the overseer is no longer neutral, who checks them? These questions are all blank in the regulations. And the blanks are not an oversight—they are space left for those with intent to maneuver.
The Fourth War: The First Collapse of the Oversight System#
The overseer of the Fourth Holy Grail War (circa 1994) was Risei Kotomine—Kirei Kotomine’s father. On paper, Risei was a venerable old priest who presided over the church, managed the records of Command Spells, and when Caster (Gilles de Rais) and Ryuunosuke Uryuu committed mass child murders and openly exposed traces of magecraft, he used his authority as overseer to mobilize the Church and the Mage’s Association to cover up the disturbance and issued an extermination order—with additional Command Spells as a reward for those who completed the extermination.
On the surface, this was a textbook overseer intervention: the offending faction was designated a public enemy, the rhythm of the war shifted from free-for-all to collective extermination, and the system worked.
But the relationship between Risei and Tokiomi makes this narrative fall apart at the slightest poke. Three years before the war, the two had already formed a secret alliance: Risei arranged for his son Kirei to participate in the war under the dual identity of ‘Church Executor and Tohsaka disciple,’ secretly assisting Tokiomi in obtaining the Grail. Kirei summoned Assassin (Hassan-i Sabbah) to handle intelligence warfare, paving the way for Tokiomi’s Archer (Gilgamesh). The overseer’s own son was a participant, and the overseer himself was using his ’neutral’ position to provide institutional cover for a specific faction.
The Caster extermination order, viewed in this context, takes on a completely different flavor. The reward mechanism of additional Command Spells might be reasonable in itself, but when the overseer has already secretly allied with a certain faction, ’neutral mediation’ becomes ‘using institutional tools to strengthen an ally.’ This is not just Risei’s problem—it is that the regulations themselves set up no firewall to prevent the overseer from converting neutral authority into factional advantage.
What followed was even more fatal. In Volume 3, Act 11, after the Caster incident was resolved, Risei met with the ‘meritorious Masters’ according to the rules, but was shot dead on the spot by Kayneth (Lancer’s Master) using the Command Spell reward mechanism, and the blame was shifted to Kiritsugu Emiya. The overseer was dead. The institutional authority physically vanished at that moment. And what happened next completely exposed the second black hole in the regulations: there was no provision whatsoever stipulating who would succeed the overseer after death, how the succession would occur, or what qualifications the successor needed to meet.
The Succession Black Hole: The Person Least Suited to Be Overseer Became the Overseer#
After Risei’s death, Kirei Kotomine discovered his father’s body. By this point, Kirei had already completed a reversal of stance from ’executor within the Tokiomi-Church cooperative system’ to ‘core destroyer in the latter half of the Fourth War’: after being marginalized by Tokiomi, he allied with Archer (Gilgamesh), stabbed his teacher in the back with the Azoth Sword gifted by Tokiomi, and seized the contract with Archer. By Volume 4, Act 15–16, Kirei had already obtained the vessel of the Holy Grail (Irisviel), set the Fuyuki Civic Hall as the final battleground, and engaged in the final showdown with Kiritsugu Emiya.
The end of the Fourth War was catastrophic: Kiritsugu ordered Saber to destroy the Holy Grail, but the Grail had already been tainted by Avenger (Angra Mainyu, ‘All the World’s Evils’) during the Third War, and destroying the vessel instead caused the black mud to overflow, triggering the Great Fuyuki Fire. Gilgamesh was incarnated (gained a physical body) through contact with the black mud, allowing him to remain in the present world. Kirei Kotomine himself was also revived, given new bodily life by the black mud.
And then, this man who had killed his own teacher, allied with a Heroic Spirit from the previous war, and been resurrected by the black mud—became the overseer of the Fifth Holy Grail War.
There was not a single clause in the oversight regulations to prevent this from happening. No recusal clause stating ‘former participants may not serve as overseer.’ No conflict-of-interest clause stating ’those with a contractual relationship with a living Heroic Spirit may not serve as overseer.’ No qualification review from higher levels of the Holy Church. Nothing. Risei died, Kirei took over—and the system silently completed the handover.
The Church’s Rule Explanation: The Filtered ‘Truth’#
Back to the Fifth. In fate_04, Rin Tohsaka brings Shirou Emiya—who had just been killed by Lancer and resurrected, and had inexplicably become Saber’s Master—to Kotomine Church. Kirei, in his capacity as overseer, explains the rules of the Holy Grail War to Shirou: it is a ritual repeatedly held in Fuyuki, currently in its fifth iteration; Masters cannot withdraw at will once they possess Command Spells; seven Servants vie for the Holy Grail—and so on.
An ordinary high school student who had just been dragged into a killing ritual, facing a gentle and polite priest, hearing a set of institutional explanations that sounded reasonable and self-consistent. What reason did he have to doubt? He hadn’t even figured out what magecraft was yet.
But looking back at this scene with the reader’s hindsight, Kirei, in his church explanation in fate_04, systematically concealed at least the following facts:
The Holy Grail has been tainted. After Avenger (Angra Mainyu), illegally summoned by the Einzberns in the Third War, was absorbed into the Grail, the interior of the Grail has been tainted by ‘All the World’s Evils,’ and any wish will be twisted into a method of destruction. This information is not revealed until the Fate route, fate_13–fate_15.
The Heroic Spirit from the previous war is still alive. Gilgamesh was incarnated by the black mud and has lurked in Fuyuki for ten years, and the resources sustaining his continued existence are—as revealed in the underground chapel of the church in fate_15—the orphans from the Great Fuyuki Fire whom Kirei imprisoned beneath the church, continuously extracting their life and suffering.
The overseer himself was a core participant in the previous war. Kirei would not tell Shirou that the ’neutral priest’ before him had killed his own teacher ten years ago, allied with Gilgamesh, and fought a life-or-death battle against Shirou’s adoptive father, Kiritsugu Emiya, in the finale.
These are not ‘forgotten to mention.’ This is deliberate selective disclosure. And the regulations are silent once again—there is no clause requiring the overseer to disclose to new participants the true state of the Holy Grail, the leftover issues from the previous war, or the overseer’s own conflicts of interest.
The First Driver of Chaos: When the Entry Point to the System Is Itself a Trap#
The chaos of the Fifth Holy Grail War is usually attributed to various specific factors: Sakura Matou being transformed into an incomplete Holy Grail by Zouken; Caster (Medea) illegally summoning Assassin (Sasaki Kojirou); the existence of Gilgamesh as an irregular Heroic Spirit; the appearance of the Shadow… But all these ‘breakdowns’ share a common upstream condition: when participants enter the war, they know nothing about its true nature.
And the creator of this information asymmetry is precisely the overseer who is supposed to ensure information symmetry.
The moment Shirou walked into the church in fate_04, he thought he was making an informed choice—learn the rules, then decide whether to participate. But in reality, the information he received had been carefully filtered by someone who had already hollowed out the entire system. He did not know the Holy Grail was a source of taint, did not know that orphans from the fire were imprisoned beneath the church, did not know that the ‘surviving Heroic Spirit from the last war’ was somewhere in Fuyuki, sipping wine and waiting for the show to begin. What he signed was a contract whose very terms had been tampered with.
This is not ’the rules had loopholes so someone exploited them’—this is the design of the rules themselves never considered the possibility that ’the overseer might be an enemy.’ And it is precisely this institutional blindness that allowed Kirei to legally stand in the church, smiling, and recite to every new participant the same spiel he had already betrayed for ten years.
From the secret alliance between Risei and Tohsaka in the Fourth, to the succession vacuum after Risei’s death, to Kirei’s systematic concealment of the Grail’s truth as overseer in the Fifth—when you string this line together, the ‘deliberate ambiguity’ of the Holy Grail War’s oversight regulations is not a bug, but a feature. It created a position with almost no checks on its power and a complete absence of accountability mechanisms. Whoever sits in this position holds the discursive power to define the ‘rules.’ And when the person sitting in this position is Kirei Kotomine—a man who feeds on the suffering of others and takes aesthetic pleasure in scenes of destruction—the Fifth Holy Grail War could never have proceeded ’normally’ from the very beginning.
The moment that church door opened, the chaos had already begun. It’s just that Shirou would have to wait until much later, standing in the underground chapel, looking at the remains of those orphans drained of life, to understand that every ‘rule’ the priest told him that night was a lie.