Written by Hikaru Sakurai and Kinoko Nasu.
The Singularity was located in A.D. 1273, in the Holy Land around Jerusalem. The roots of the Singularity lie in several events. Firstly, someone who should have died midway through the Ninth Crusade was given a Holy Grail, and using its power, the expeditionary force reached the Holy Land, burning the lands and slaughtering the people living there. However, in their greed, they summoned Ozymandias who subsequently confiscated the Grail and set about building his kingdom there. Having lost the Grail, the expeditionary force lost ground and were eventually cornered by the people of the Holy Land. When they were cornered, a Servant identifying himself as Richard the Lionheart, but displaying different behavior and appearance, appeared and summoned his own crusaders. The crusaders subsequently captured the expeditionary force and occupied the Holy Land.Secondly, Bedivere did not return Excalibur to the Lady of the Lake, Artoria Pendragon was unable to die when she was fated to after the Battle of Camlann, ending up becoming a wandering ghost. With Rhongomyniad still in hand, she eventually turned into a Divine Spirit, who would come to be known as the Lion King. The Lion King was aware of the incineration of humanity and planned to store a selection of human souls into Rhongomyniad to preserve humanity in some form. After arriving in the Singularity, the Lion King summoned the Knights of the Round Table (with the exceptions of Bedivere and Galahad) and told them of her plan. Aware that some of them wouldn't follow her, she gave them until sunset to decide where they stood. In the subsequent battle, the Knights who decided to follow the Lion King slaughtered their fellow knights who chose to stand against her. The Lion King then bestowed Gifts on the surviving knights, with the exception of Agravain.
The Knights of the Lion King exterminated the crusaders, with the expeditionary force being annihilated along with them. During the battle with the one claiming to be Richard the Lionheart, Gareth sacrificed herself to give the others an opportunity to kill him, unable to bear the guilt of killing her fellow knights any longer. Her brother Gawain was the one who struck them both down. Afterwards, the Lion King and her knights established the Holy City of Camelot in the Holy Land. This occurred about half a year before Chaldea's arrival.
Welcomed by the Sand
Supper of the Sun King
To The East
The Wailing Wall
Adventure in the East Village
Mordred, the Raider Knight
Sanzang Returning from the West
Flower of Poison, Blade of Iron
Feast, West Village
The Evening Bell of Death
Village in Flames
To the Desert of Atlas
The Hidden Research
The God King Ozymandias
The Eve of the Decisive Battle
- Anti-Villain: Unlike the previous Singularity antagonists, the Lion King and the Knights of the Round Table aren't fighting to destroy humanity but to save it (even annihilating the Crusader armies that were originally going to be fighting for the Grail and turned into a Demon Pillar)...the problem is that they have a very specific criteria of those they want to save, and the method through which they will "save" humanity turns out to be far less benevolent than it sounds...
- Bait-and-Switch: Unlike with Okeanos, the grail Ozymandias has is the one the player and Chaldea are looking for. However, he's not destroying humanity in this singularity. Altria Pendragon (Lancer) as the Lion King and the Knights of the Round Table are filling that role.
- The Battle Didn't Count: The Lion King insists on this after her defeat. She's not exactly wrong, given that she now has Excalibur and is still rearing for battle, but the loss of Rhongonmyniad means the Singularity can't sustain itself anymore, causing her to disappear while the protagonist escapes with the Holy Grail. Of course, Altria's habit of being a Sore Loser can't be ignored either.
- Black Comedy: Ozymandias' head somehow being separated from him when you initially meet him is Played for Laughs.
- Call-Back: Xuanzang's debut event was titled "Sanzang Coming to the West" when released in America. The section of Camelot where she debuts is referred to as "Sanzang Returning From the West".
- Character Alignment: This was an element of the franchise since the original Fate/stay night, but only here it is relevant In-Universe, as the Lion King creates an utopia by only allowing Lawful Good people inside her holy city.
- Dangerous Forbidden Technique: Bedivere, Da Vinci, Mordred, Arash, Xuanzang, Ozymandias, Nitocris and Hassan of the Cursed Arm were shown to have powerful abilities that can result in the user's death. Bedivere, Mordred and Nitocris attempt to use them to lethal levels but quit after being chastised by Arash (the former two) or Ozymandias (Nito); for Da Vinci and Cursed Arm, they manage to survive but only after being bailed out by Lancelot and the First Hassan respectively; the rest actually go through with their own attempts.
- Dying Moment of Awesome: To the point of overuse in the later half of the singularity, with Arash, Xuanzang, Ozymandias and Cursed Arm using the aforemontioned Dangerous Forbidden Technique. Cursed Arm gets better though.
- Debut Queue: Altria Pendragon (Lancer), Bedivere, Gawain, and Tristan are all added to the story gacha after completing this singularity. Likewise, the release of this chapter saw the debuts of Saber Lancelot, Ozymandias, Hassan of Serenity, Nitocris, and Tawara Toda in the gacha.
- Early-Bird Cameo:
- King Hassan, who's later revealed to be the Grand Assassin, makes his appearance in this chapter. However, he can't be used as a support unit.
- Sherlock Holmes appears in the Atlas Institute, researching Solomon and helping the protagonist research the current crisis. He can't be used a a support unit either.
- Gameplay and Story Integration: Lots of it here.
- Assassins move easily in the magically controlled winds of the desert because of their "Protection from Wind" skill, or from some other evasion skill granted to them.
- Arash doesn't have an NP bar when you fight him. It's because if he uses it at that time, he's gone from the story. He doesn't use it until his Heroic Sacrifice.
- Knights of the Round Table gain "grail bonuses" related to their myths. Of particular note is Tristan, whose boost switches his disposition and makes him immune to poison. This results in him being a Affably Evil Jerkass since he normally is one of the most empathetic members of the group. In gameplay, he takes extra damage from Sabers, but does extra damage to other classes.
- Earn Your Happy Ending: Cursed Arm has lost a lot during the singularity. In the end, however, he was free of the Hassan title thanks to King Hassan's Loophole Abuse, allowing him to have a normal life with his son, Rushd.
- Godzilla Threshold: Attempting to get help from King Hassan is this, as he's likely decapitate whoever needed his help in the first place.
- Kill 'Em All: With the exception of the protagonist, Mash, Da Vinci, Hassan of the Cursed Arm and Tawara Touta, every single characters from this singularity, good guys and bad guys, died.
- Promoted to Playable: In a sense - while Xuanzang had debuted prior to this event, she was a limited servant; this event saw her added to the gacha permanently.
- Retirony: Subverted, as Cursed Arm Hassan winds up tripping so many death flags that, instead of coming to claim his soul as promised, King Hassan shows up to insist that "Cursed Arm" is already dead before congratulating the assassin formerly known as Cursed Arm Hassan on being the only (ex-)Hassan to successfully retire from his post instead of dying in the line of duty.
- The Reveal: The Heroic Spirit fused with Mash is none other than Galahad. There were hints of this since the fight with Altria Alter in Fuyuki, but here is where it's officially revealed.
- Holmes reveals that Dr. Roman came completely out of nowhere before suddenly being a part of Chaldea. He goes on to state that he does not trust Roman, suspecting him to be connected to Solomon.
- A truly epic one comes at the end when Bedivere reveals himself to be human, not a Servant, who has been traveling for well over 1,500 years to fulfill his oath to Altria.
- Secret Test of Character: Ozymandias lets the protagonist and servants wander around Camelot first, in order to see the horrors of the Lion King's kingdom before he decides to help the protagonists. And even then, he fights them via Demon Pillar to see if they're truly worthy.
- Shoo Out the Clowns: The first casualty of the climax is Xuanzang Sanzang who is a Cloud Cuckoo Lander with Tawara Touta serving as her straight man.
- Sole Survivor: Hassan of the Cursed Arm is the only Hassan alive after the final battle. And even then, it was by a hairstrand.
- Spoiler Title: If you paid attention to the introduction of the story, you'd know that you're supposed to travel to Jerusalem, but you then see that the place you've been teleported into is something else entirely. It has parts of Egypt, Jerusalem, and most of all, Camelot.
- Story-Breaker Power: King Hassan isn't threatened by any of the Knights of the Round Table or Ozymandias (only failing to kill the latter because he was inside his temple), and shows that he could easily kill the opposing factions and potentially deal with the Lion King by himself. He just prefers to be a Sink-or-Swim Mentor for the other Hassans and the protagonist.