Fate/Accel Zero Order

Fate/Accel Zero Order refers to a an event, part of a collaboration between Fate/Grand Order and Fate/Zero, which occurred during the Human Order Incineration Incident. It involved a small Singularity that manifested in the coordinates of Singularity F in an alternate timeline ten years prior during the Fourth Holy Grail War.
==Setting==
The Singularity shares a similar background to the Fourth Holy Grail War of the original timeline but with significant differences. Kiritsugu Emiya and Irisviel von Einzbern never met nor was he hired by the Einzberns to serve as Artoria Pendragon's Master. Instead she became a proper Master in the war with Artoria as her Servant, while he contracted with the World to become a Counter Guardian. So unlike the original Fourth Grail War, the Einzberns prove to be the superior faction. However, the Counter Force sensing that the Einzbern's victory will cause the activation of Angra Mainyu, summoned Kiritsugu to stop the war before its completion.
==History==
===Prelude===
Romani Archaman calls Ritsuka and Mash to the command room early in the morning to inform them a new Singularity has manifested. Its coordinates are the same as Singularity F, but its temporal axis corresponds to a decade earlier. Romani is uncertain there is a Holy Grail, but an extremely similar response has been observed. He can't explain if it's possible for a Grail to manifest frequently at the same point, which is why he brought in someone who might: Lord El-Melloi II.Fate/Grand Order - Fate/Accel Zero Order - Prelude
El-Melloi II admits he is familiar with Fuyuki, but his knowledge is estranged from the history recorded by Laplace. Romani finds that to be expected because with human history incinerated, many different possibilities have been mixed in with Chaldea's observational results. He expects CHALDEAS doesn't exist in El-Melloi II's timeline, and he isn't sure which of their worlds is the proper history. But it's obvious they are close to each other, otherwise El-Melloi II couldn't be summoned.
El-Melloi II understands Romani is speaking about the cluster of parallel worlds within the Primary Branch, but that is outside his purview, nor is it something Ritsuka needs to hear either. So he will only tell the Chaldeans what he knows based on the events which occured in his world.
He reveals the Holy Grail War occured five times in his world while only once in Chaldea's in 2004. The Singularity's temporal axis places it at the time of the Fourth Holy Grail War, so it's unsurprising a Grail would be detected there. But El-Melloi II notes it should be impossible to observe the light of civilization in the past on a normal temporal axis with human history incinerated. He recognizes the Singularity is still a stain on human history that will eventually contaminate it, though.
However, he reveals the issue with Chaldea's mission to either retrieve or destroy the Grail is that the Grail never once manifested during all five Fuyuki Grail Wars. Also, due to a certain accident, the ritual became compromised. This Grail is therefore one Chaldea mustn't retrieve nor can it be allowed to manifest. It is not a wish granter like the participants were told in truth it is a device meant to destroy the world.
El-Melloi II admits he did a lot of research on this subject, feeling it was his responsibility as a participant of the Fourth Grail War. He had also put in considerable effort to dismantle Fuyuki's Grail. The Fourth Grail War was a life-changing event for him, so he will join Ritsuka and Mash in their investigation. He, Ritsuka, and Mash then rayshift into the Singularity.
=== The Man Who Knows Fuyuki ===
Arriving in Fuyuki, El-Melloi II uses Unreturning Formation to reveal the concealed Assassin. He had anticipated her she'd come to investigate the rayshift's light, knowing she surveys the entire city with her ability to split into multiple entities. He tells Ritsuka to fight her, promising to explain everything afterward.Fate/Grand Order - Fate/Accel Zero Order - ACT-1: The Man Who Knows Fuyuki
Assassin is defeated, but El-Melloi II warns that was only one of her and she will keep attacking them. They shouldn't pose much of a threat, though, so he tells Ritsuka and Mash to defeat the moment they see them. He then urges them onward, saying they're in a race against time. He promises to explain everything along the way, starting with the most vital bits.
=== Military Intervention ===
At the wharf, El-Melloi II reveals All the World's Evils, Angra Mainyu, will activate if the required number of summoned Servants are sacrificed. He compares it to a bomb capable of destroying the world and calls Singularity F the likely result if the ritual was completed during the fifth war. The ritual began with a very different purpose and only turned toward destruction thanks to a man-made disaster in the past.Fate/Grand Order - Fate/Accel Zero Order - ACT-2: Military Intervention
But El-Melloi II points out the paradox in SHEBA detecting a Grail in this era; if the Grail has already manifested, then Fuyuki should already be in flames. Seeing that isn't the case, though, El-Melloi II theorizes the Grail detected by Chaldea differs from Fuyuki’s Greater Grail corrupted by Angra Mainyu.
He recalls tonight is when the Fourth Grail War sets into motion, which they can use. He confirms that is why he's been conscious of the time, saying it's critical they stay ahead of events. The Harbor will be key, but events catch up before El-Mello II can explain.
Irisviel von Einzbern arrives with Saber and assumes the Chaldeans are participants in the war. Saber informs Irisivel that she no longer senses Lancer's presence, even though he invited them to the harbor.
El-Melloi II reveals Saber's True Name is Artoria Pendragon and declares he and his allies will be her and Irisviel's opponent now instead of Lancer. At his behest, Ritsuka and Mash fight Artoria with the restriction of only making her retreat.
After Irisviel and Artoria retreat, Lancer, who was previously trapped by El-Melloi II’s Unreturning Formation to prevent him from fighting Artoria, confronts the group. El-Melloi II reveals Lancer’s True Name is Diarmuid Ua Duibhne, and tells him they aren’t Kayneth El-Melloi Archibald‘s enemies.
He tells Kayneth they came to support him and gives Reines El-Melloi Archisorte as his guarantor since, for certain reasons, he cannot currently divulge his name. He declines to give him an explanation until tomorrow, but he will tell him in advance that he knows Caster's current location, saying he will prove it tomorrow at noon. They will then visit him at his penthouse suite in New Fuyuki Tower 10pm tomorrow. Kayneth agrees to let the Chaldeans go unharmed, even showing himself.
After leaving the harbor, El-Melloi II explains the Greater Grail activates in a limited capacity with the fifth sacrifice. His plan is, therefore, to have at least three Servants safely withdraw the battle to keep the Grail from activating. But they will need to eliminate the Servants with whom agreement is impossible: Caster and Archer. But a confrontation with Assassin is inevitable when they go after Archer since their Masters are allied.
As for Berserker, they will need to convince his Master to join them since direct reasoning with the former will be impossible. But Berserker could still go on a rampage independent of his Master's will, whom El-Melloi II warns is physically and mentally unstable. The Chaldeans thus agree to postpone convincing Berserker’s Master.
They conclude their best chances for success are with Artoria, Diarmuid, and Rider. It was for that reason that El-Melloi II prevented a clash between Artoria and Diarmuid.
Mash asks him if he thinks the Rider faction is likely to cooperate. After a moment of silence, El-Melloi II replies it depends on how well he can get them to accept his word.
=== Second Owner ===
Later, Mash is prevented from establishing a summoning circle to get supplies from Chaldea because of the Tohsakas’ protection spell on the leyline. El-Melloi II decides they must destroy the keystones that power the spell to take the leyline for themselves. Romani worries doing so will anger the Tohsakas, but El-Melloi II reveals they summoned Archer. He then leads the Chaldeans to each keystone, the locations of which he learned from the Tohsaka's heir when she helped him dismantle the Greater Grail in his timeline.Fate/Grand Order - Fate/Accel Zero Order - ACT-3: Second Owner
=== Those Who Lurk in the Dark ===
At one of the keystone location, a dark alleway, the Chaldeans are ambushed by Caster's Sea Demon familiars.Fate/Grand Order - Fate/Accel Zero Order - ACT-4: Those Who Lurk in the Dark
=== The Meeting of El-Melloi ===
After killing the Sea Demons and destroying the keystone, the Chaldeans go to Kayneth's suite. El-Melloi II will handle the negotiations, but he will keep a telepathic channel open so he and Ritsuka can communicate in secret.Fate/Grand Order - Fate/Accel Zero Order - ACT-5: The Meeting of El-Melloi
In his suite, Kayneth confronts El-Melloi II about the fact he lied about acting on Reines’ behalf. He continues the meeting, however, because he is curious how El-Melloi II knew about the Holy Church's actions regarding Caster in advance.
El-Melloi II answers that is because all this happened in the past for him, knowing the Overseer is offering a special reward for the participant who kills Caster. He also knows Kayneth originally intended to summon Iskandar but was forced to summon Diarmuid instead when his student, Waver Velvet, stole the catalyst. He even knows it is his fiancée, Sola-Ui Nuada-Re Sophia-Ri, providing magical Energy to Diarmuid and that he has her in another room to keep her safe. Kayneth stops him before he can recite his love letter to Sola-Ui and demands to know El-Melloi II's identity.
El-Melloi II asserts he wasn't lying about acting Reines' behalf but confesses he will not receive that duty until four years from now. Everything he said is thus part of his past memories. Kayneth is skeptical El-Melloi II is a time traveler and demands a believable explanation.
=== United Battlefront ===
El-Melloi II deceives Kayneth into believing it was leadership that made it possible for the Archibalds to establish Chaldea and develop its technology in the future. He also convinces him that it was thanks to his loving relationship with his future wife that the latter's family financed Chaldea. Romani and Mash both presume El-Melloi II wanted the Lancer faction as allies first because they were the easiest to trick.Fate/Grand Order - Fate/Accel Zero Order - ACT-6: United Battlefront
But El-Melloi II informs Kayneth while they've come to ensure his future glory, they cannot intervene with the past beyond providing information. He thus encourages him to kill Caster, whose location is unknown to the other participants, first so he can get the additional Command Spell the Overseer promised.
The heroes go to the sewers where Caster is located, and battle his familiars barring the way to his workshop.
=== Hunting for Bluebeard ===
FGO Fuyuki Sewers.png|Sewers
FGO Gilles Workshop.png|Gilles de Rais's workshop
They eventually break on through to Caster's workshop, where they confront him--Gilles de Rais. They kill him, but Ritsuka wonders where his Master is. El-Melloi II warns Gilles’ Master is a murderer they must stop. After Kayneth goes to the Church to get an additional Command Spell, the Chaldeans search for Gilles’ Master.Fate/Grand Order - Fate/Accel Zero Order - ACT-7: Hunting for Bluebeard
=== Irregular ===
They find his corpse, but it is too clean of a kill to be the work of Gilles. El-Melloi questions who the culprit could be when he suddenly deploys and traps a Servant with Unreturning Formation. Said Servant is a mysterious Assassin, who wasn't part of the Fourth Grail War El-Melloi II knows and whom he suspects is connected to why 1994 Fuyuki became a Singularity. The Chaldeans battle the mysterious Assassin to capture and interrogate him.Fate/Grand Order - Fate/Accel Zero Order - ACT-8: Irregular
Unfortunately, he escapes when Iskandar and Waver charge in and destroy the formation. Waver is disappointed he and Iskandar aren't the first ones here like he thought they'd be. Ritsuka and Mash both recognize Waver's face.
El-Melloi II reprimands Waver for thinking he and Iskandar would be the first ones when he knowingly used a primitive method to locate Gilles' workshop. By pure luck, his problems always resolve themselves in the end, and because of that, he starts to overestimate himself. That is why he will never improve.
Waver is confused as to why a stranger is lecturing him. He then wonders if El-Melloi II is Caster or his Master. El-Melloi II admonishes him severely for failing to analyze the current situation and hopes he dies. But Waver can tell status-wise El-Melloi II is a Caster and still assumes he is the dangerous Caster the Overseer spoke of. El-Melloi II berates him for being unable to tell he is a Pseudo-Servant, calling him pathetic. Waver is confused by the term and the fact there are two Casters.
Iskandar tells Waver that El-Melloi II isn’t the owner of the workshop. He then tries to pick a fight with El-Melloi II for picking on his Master. The Chaldeans retreat much to his disappointment.
El-Melloi II berates Iskandar for being protective toward his Master. He tells the others they'll leave the Rider faction alone, as he knows they will not ever fight the war seriously. Ritsuka and Mash both realize Rider is a touchy subject with El-Melloi II.
=== The King of Knights Returns ===
Later, Mash finally establishes the summoning circle, but Artoria appears and challenges the Chaldeans to a fair fight. El-Melloi II is unconvinced as he knows she serves a decoy for the assassin hired by the Einzberns to ambush the enemy.Fate/Grand Order - Fate/Accel Zero Order - ACT-9: The King of Knights Returns
Irisvie calls that a false accusation and demands to know El-Melloi II's intentions, knowing he isn't an officially summoned Servant. The Chaldeans fight Artoria to get her and Irisviel to retreat again.
=== The Mysterious Assassin ===
During the battle, however, Mash suddenly protects Irisviel from the mysterious Assassin's ambush. He tells Irisviel that as Bearer of the Grail, killing her is the quickest way to dismantle the Grail. Artoria fights him to protect Irisviel, prompting the Chaldeans to help her so to not lose her.Fate/Grand Order - Fate/Accel Zero Order - ACT-10: The Mysterious Assassin
Beaten back, the mysterious Assassin questions why the Chaldeans are interfering when they're not even participants. El-Melloi II asks him why he is trying to kill Irisviel. The mysterious Assassin refuses to say and retreats, saying he is commanded from the bounds beyond human understanding. 
El-Melloi II convinces the Saber faction he and the others aren't their enemies. He then asks Irisviel if she knows the mysterious Assassin's identity. Irisviel says she doesn't, so El-Melloi II makes solving his identity their immediate goal.
Irisviel confesses though she never met him before, she feels she and the mysterious Assassin are deeply related. It is as if he is only here to kill her and she is only here to be killed by him. Artoria refuses to believe that and vows to protect her and see her victorious. 
She recognizes Mash's shield but declinces to say anything, feeling it isn't her right to say if Mash doesn't know herself yet.
=== Strategist's Trap ===
Though peace has been established with the Saber faction, Romani points out they're still enemies with the Lancer faction. El-Melloi II understands the issue of being friendly with both sides and decides the best course is to persuade Kayneth by taking advantage of his narcissism. But before they head back to his suite, the Chaldeans first defeat another of Assassin's fragments.Fate/Grand Order - Fate/Accel Zero Order - ACT-11: Strategist's Trap
In his suite, Kayneth informs El-Melloi II that, per his suggestion, he had sent a familiar to the Matou mansion last night and negotiated with the Berserker faction. They have agreed to join them if they're provided with an opportunity to face Archer.
El-Melloi II tells Kayneth that the Holy Grail War is a conspiracy by his family's enemy, the Trambelios. Its purpose was to get him away from the Clock Tower then increase their influence in the Mage's Association while he’s away. El-Melloi II claims he and the others came to the past to rescue him from said plot. However, they couldn't warn him until they obtained irrefutable evidence in the past that a conspiracy existed.
They got said evidence last night from the Tohsakas after they destroyed every leyline in the city. Not wanting to lose their land rights over it, the Tohsakas confessed to colluding with the Trambelios to create this fake war. The Overseer and the other participants were all merely decoys to make the farce more believable. Kayneth is convinced of the conspiracy and persuaded by El-Melloi II to hurry back to London with Sola-Ui and stop the Trambelios' plot.
Diarmuid is eager to accompany his Master, which El-Mellloi II is certain will please Sola-Ui. But Kayneth, aware of his fiancée's infatuation with his Servant, orders Diarmuid by the Command Spell to stay and win the war for the sake of his family's reputation. He lends him to the Chaldeans, who will represent his family in his stead.
Before he goes, though, he has El-Melloi II confirm he found a draft for a love letter in his study. He says he would never anyone search his room while something like that was still in it. He assumes the study El-Melloi II refers to is one whose master never returned.
El-Melloi II confirms Kayneth's assumption, for which the latter thanks him. El-Melloi II appreciates his old master's words, calling him the lord he aspired to be and his talents a treasure to the Clock Tower.
Outside, Romani reminds El-Melloi II that the Singularity is an irregularity that will not affect real history once it's gone. Thus, his actions here will not change what happened in his timeline. It is theoretically impossible to alter the past via rayshift.
El-Melloi II is unware he cannot change his past, but he refuses to make the same mistakes twice and be forced to realize his own powerlessnesss. His regret is his alone, though he is ashamed for wasting Ritsuka and Mash's time. But much to his appreciation, Ritsuka and Mash agree with his plan regardless of the result. The Chaldeans then go to meet with the Berserker faction.
=== Discussing the Holy Grail ===
Meeting with Berserker's Master, Kariya Matou, in a forest, El-Melloi II assures him Berserker's Noble Phantasm can defeat Archer. As for where they battle one-on-one without interfere, he recommends the nearby Einzbern Castle. Archer is there right now, having a discussion with Artoria and Iskandar.Fate/Grand Order - Fate/Accel Zero Order - ACT-12: Discussing the Holy Grail 
The heroes interrupt the meeting between the three kings, and for this trangression, Archer--Gilgamesh--decides to punish them himself. With the Rider and Saber factions having no issue with this, Berserker battles Gilgamesh with the Chaldeans' help.
=== Battle Royale ===
Gilgamesh is defeated, but Kariya passes out from the effort, causing Berserker to go out of control and attack Artoria. The heroes fight him as they cannot lose Artoria and he has outlived his usefulness with Gilgamesh gone.Fate/Grand Order - Fate/Accel Zero Order - ACT-13: Battle Royale
Berserker is nearly defeated, but Iskandar protects him before he can be finished off. He explains he is joining Berserker to fight El-Melloi II out of sheer dislike and suspicion. He calls him a greater threat than a mere enemy for trying to disrupt the war and warns Artoria and Diarmuid they’ll be his enemies if they ally with El-Melloi II.
Diarmuid prepares to fight him, but El-Melloi II warns they’re only allowed to defeat four Servants. Iskandar leaves, taking Kariya and Berserker with him, vowing to fight El-Melloi II once Berserker recovers.
=== The Shadow Chasing Irisviel ===
After Iskandar is gone, the mysterious Assassin arrives to kill Irisviel again, needing to do so before the war concludes. That confirms for El-Melloi II that the former is after the Grail's vessel. Their goals are similar, but their methods are different.Fate/Grand Order - Fate/Accel Zero Order - ACT-14: The Shadow Chasing Irisviel
El-Melloi II explains Irisviel is only pretending to be Artoria's Master when, in truth, she is the Lesser Grail, collecting the souls of fallen Heroic Spirits. Irisivel denies she is pretending, but El-Melloi II still believes she is nothing but bait while the true Master remains hidden. Artoria asssures Irisiviel is her Master. Irisviel shows her Command Spells to prove it, much to El-Melloi II's shock. The mysterious Assassin attacks.
After the heroes best the mysterious Assassin, El-Melloi deduces he is a Counter Guardian. The mysterious Assassin questions how he came to that conclusion, to which El-Melloi II confesses he, Ritsuka, and Mash are from a different temporal axis, thus giving them an overview of the situation. They know the activation of the Greater Grail will destroy the world, and he reveals Fuyuki is the source of the Singularity. 
He deduces Irisviel being both the Lesser Grail and a Master is why this war differs from the one he knows. The Einzbern's ultimate homunculus was meant to appear ten years later. But Irisviel being that sort of Master now with a powerful Servant meant victory for the Einzberns was certain, which prompted the Counter Force to intervene.
The mysterious Assassin is surprised the Counter Force never intervened in El-Melloi II's fourth Grail War. El-Melloi II says it wasn't a factor during the third war, while there was a 50/50 chance during the fourth and fifth.
Romani concludes the Singularity is the embodiment of the "what-if" scenario where the Einzberns were the superior contestant in the Fourth Grail War. El-Melloi II concurs and concludes Irisviel’s Magic Circuits are likely the Grail Chaldea detected, even calling her a pseudo Holy Grail.
Irisviel still confused by the situation asks El-Melloi II what he meant when he said the world will be destroyed if the Grail is completed. El-Melloi II agrees to explain everything. He tells the mysterious Assassin to follow along as well, promising a way to accomplish his task without killing Irisviel. He cannot promise it will be simpler, but he asks him if he still wants to kill Irisviel regardless.
The mysterious Assassin answers he doesn't know, as he had resigned himself to thinking there was no alternative. But now that El-Melloi II is telling him there is an alternative, he is faced with an inner conflict he cannot explain. If there is an alternative with Irisivel, he would like to explore it. He wonders why he feels this way, having never experienced it before. El-Melloi II tells him that is because he still has a human heart, a foolish but noble soul from before he became part of the Counter Force.
=== To the Greater Grail ===
Outside the Matou mansion, Kariya tells the Rider's faction how he became Berserker's Master. Waver asks what he plans to do next now Gilgamesh is gone. Kariya replies he is going to kill Tokiomi Tohsaka, seeing him as powerless without his Servant. Iskandar punches him in response, disappointed he would prioritize killing Tokiomi over the one he wanted protect and save: Sakura Matou.Fate/Grand Order - Fate/Accel Zero Order - ACT-15: To the Greater Grail
He then attacks the mansion, burning the worms in the basement and capturing Sakura. He says she is his slave now, but he agrees to give her to Kariya in exchange for right hand and Command Spells. Kariya concedes, wanting to save Sakura over continue being Berserker's Master.
Iskandar cuts off Kariya's right hand. The crest worms come with it, prioritizing the Command Spells over their host. Iskandar orders Mithrenes take Kariya and Sakura to a hospital outside of Fuyuki before leaving with Waver for next battle.
Zouken Matou returns to see his home burning and his worms dead. He assumes Kariya is responsible, seeing that he and Sakura are both missing.
He then noticess Berserker, who is about to disappear from lack of magical energy. He also sees Kariya's Command Spells on the ground and concludes he had abandoned the war. He takes Berserker with him to get revenge.
Meanwhile inside the Greater Grail's cavern, El-Melloi II has told Irisivel of the Grail' corruption. He has also decided to forgoe his original plan since they failed to recruit Iskandar. Instead, they will destroy the Grail directly. But first the heroes battle Assassin and her remaining selves.
=== King's Pride ===
Assassin is defeated once and for all. The mysterious Assassin suspects her Master didn't know how to use her correctly. El-Melloi II deduces the Masters must have switched. He suspects Tokiomi, having lost Gilgameshh, was plotting a comeback by switching to Assassin.Fate/Grand Order - Fate/Accel Zero Order - ACT-16: King's Pride
The heroes enter the Grail's chamber, the magical energy radiating from the so-called wish granter confirming its corruption. Diarmuid, sensing the great evil within, questions if it is safe to break it. El-Melloi II assures Angra Mainyu won't awaken with only three Servants defeated. Even if it does overflow, it would be a mass of ambigious curses without purpose, something they can handle with their current forces.
Iskandar and Waver then come charging in. The former is still intent on fighting El-Melloi, not caring about the Grail's corruption, because he wants to entertain the latter.
El-Melloi II is incredlous Iskandar wants fight him for such a selfish motive when the world is facing a crisis. Iskandar calls him a worthy opponent and feels he won't be satisfied unless he defeats. El-Melloi II laughs and requests Ritsuka's permission to put everything asside so he can focus solely on fighting Iskandar. Ritsuka gives his approval, so El-Melloi II fights Iskandar.
=== Wish of the Three Founding Families ===
Iskandar is defeated, leaving him impressed by El-Melloi II's Noble Phantasm. El-Melloi II says he got it by accident, believing he wouldn't be a match for Iskandar with his own ability. Iskandar flicks his forehead and tells him it doesn't matter whose power you wield, only how you wield it. He had expected El-Melloi II would understand that if he saw his Ionioi Hetairo. He disappears, satisfied with the battle.Fate/Grand Order - Fate/Accel Zero Order - ACT-17: Wish of the Three Founding Families
El-Melloi II cries, confusing Waver as it should be him crying instead. El-Melloi II admits he is right, but he never thought he'd have such a meeting in his lifetime. Unfortunately, his grieving leaves him open to a sudden ambush by Zouken and Berserker.
Zouken is upset Irisviel would help to dismantle the Greater Grail, asking she has forgotten the wish of the Founding Three. Irisviel responds it's obvious the ritual failed long ago, stating Heaven's Feel will never be achieved with the Grail in its current state. Zouken, however, does not care, obsessed with seeing their labor of the past 500 years come to fruition. He will therefore never give up the Grail and sics Berserker on the heroes to protect it.
=== Fallen Grail ===
Berserker is defeated. Unfortunately, he is the fifth Servant to fall, meaning the Grail is ready to activate. Zouken extracts magical energy from Irisviel to hasten its awakening. But it will be an imitation like Irisviel, but a true vessel.Fate/Grand Order - Fate/Accel Zero Order - ACT-18: The Fallen Grail
Suddenly someone resembling Irisviel emerges from the Grail, designated Black Iri. Zouken recognizes her as Justeaze Lizrich von Einzbern and realizes his role was to recall her visage. Black Iri devours him and targets the heroes next as five Heroic Spirits weren't enough to fill her. Irisivel realizes Black Iri isn't her ancestor Justeaze, but a tainted Grail polluted by All the World's Evils.
Diarmuid, Artoria, and Romani all conclude they have no chance of winning against Black Iri without El-Melloi II, as the absence of even one Servant is critical. Artoria and Diarmuid hold her off while the others evacuate, taking the unconscious El-Melloi with them.
Diarmuid, Artoria, and Romani all conclude they have no chance of winning against Black Iri without El-Melloi II, as the absence of even one Servant is critical. Artoria and Diarmuid hold her off while the others evacuate, taking the unconscious El-Melloi with them.
Outside of the chamber, El-Melloi II regains consciousness. His Spirit Core is undamaged, but he can't move his body.
After hearing about the situation, he tells Waver that he is key and offers to give him power, well aware of his inferiority complex. Waver accepts so El-Melloi II instructs him to take his hand and pray: "The art of certain victory, the mode of harmonizing with charges, is a matter of opportunity."
Waver does as instructed, turning himself into Zhuge Liang's new temporary vessel. The heroes then head back to the chamber to help Diarmuid and Artoria fight Black Iri.
After she is destroyed, Diarmuid and Artoria both disappear since the Grail was destroyed.
El-Melloi II declares the Grail that Chaldea detected is gone. He asks Irisviel what she intends to do now she can no longer become the Grail. 
Irisviel feels her existence is without value now the Holy Grail War has been rendered meaningless. She also can't return to the Einzberns since she helped destroy the Grail. Mash suggests returning to Chaldea with them, as their original goal was to retrieve the Grail, which Irisviel agrees to. 
El-Melloi II confirms to Waver that they'll all be leaving. That includes Zhuge Liang, so Waver will return to his ordinary mediocre self. He tells him to study and become strong while he can as the power he will be his someday.
Waver compares El-Melloi II to Iskandar, though El-Melloi II believes he can’t match Iskandar yet. Waver asks him if he's trying to become Iskandar's equal. El-Melloi II ignores the question and tells Waver he'll guide him back to the surface.
The mysterious Assassin and Irisivel both realize they have a strange yet pleasant connection. He is satisfied he could protect something without sacrifice, for which he thanks Irisviel. Irisviel thanks him in turn, and says goodbye, glad that she met him.
The Chaldeans return home with Irisviel. She is taken straight to Leonardo da Vinci for a checkup. El-Melloi II is taken to the ICU, where he will need to stay for a while. Mash says it was thanks to him and the Counter Guardian Assassin they succeeded.
Romani finds it interesting the Counter Force still functions even with human history incinerated. He explains when Ritsuka asks that the Counter Force is, in theory, a force that acts to preserve humanity. Those who accomplished rare feats of valor in their life are summoned by it throughout space and time to eliminate anything that threatens humanity. They are Masterless Servants summoned to fight for all eternal. Romani cannot understand their feelings but expects they must endure unspeakable anguish.
Mash says she couldn't imagine being summoned without a Master. It is her bond with Ritsuka, her Master, that gives her the strength and courage to overcome fear. Fighting without them would be too cruel for her.
Meanwhile, in the Singularity, the mysterious Assassin urges someone to come out already, saying no one will interfere. This other person is irritated the mysterious Assassin knew he planned to ambush him. A person of pure blackness emerges from the Grail.
He asks the mysterious Assassin why he didn’t warn the others of him since they only destroyed the vessel and not him, Angra Mainyu, the contents. The mysterious Assassin answers he didn’t want to rely on others from another world to destroy him, whose curse solely belongs to this world. Angra Mainyu criticizes him for continuing to be a Hero of Justice even after death. Assassin has no regrets for his chosen path, though, saying they’ll both curse and save the world, respectively.
With a grin, Angra Mainyu agrees to battle the mysterious Assassin, revealing his heavily tattooed body. But first he wants to know his opponent's name, expecting, unlike him, he still remembers his name.
The mysterious Assassin removes his hood, revealing his face, and give his name as Kiritsugu Emiya. He proclaims he will save the world now and forever. He and Angra Mainyu then begin their battle.
=== Retrieving the Holy Grail ===
Ritsuka and Mash later return to the Grail’s chamber and meet Angra Mainyu. After fighting Angra Mainyu for being a pervert, the pair meets Irisviel. Irisviel explains she isn’t the Irisviel that Ritsuka and Mash worked with, rather she is more like the spirit of the Grail. Angra Mainyu claims she severely beat him until a moment ago. Irisviel then reveals Chaldea failed to destroy the Grail completely, resulting in Irisivel being split into four elemental versions. While they’d normally be similar to the original Irisviel, they hold a grudge against Ritsuka. Now they are loose in Fuyuki. Irisviel and Angra Mainyu task Ritsuka and Mash with defeating the Iri elementals, one they eventually complete.Fate/Grand Order - Fate/Accel Zero Order - ACT-EX: Retrieving the Holy Grail
==Participants==
Servants
Non-Servants
Designation	Identity 	Affiliation
Master 	Irisviel von Einzbern 	N/A
Master 	Kayneth El-Melloi Archibald	N/A
Master 	Waver Velvet 	N/A
Master 	Kariya Matou 	N/A
Magus 	Zouken Matou 	N/A
==References==
Category:Locations in Fate/Grand Order‎
Category:Grand Orders
Category:Fuyuki City