People have been disappearing in Central Asia for unknown reasons in 2000 AD and even worse, several Servants from Chaldea have also unwittingly been Rayshifted over to this new Singularity, a giant underground hollow space. Due to one of the remaining Demon Pillars being the most likely suspect, Chaldea has once again been granted permission to send the protagonist to investigate the disappearances.
Welcomed by the Subterranean World
At the Amazon Village
Heading to Ys
The Pirate Princess Lewdly Smiles
To the Nightless City
The Brilliant Fortress City
Invading El Dorado
Flames of Progress
Decisive Battle in El Dorado
King of Slaves
The Story Comes to Fruition
Women of Agartha
- Arc Villain: Scheherazade and the Demon God Pillar Phenex, who attempted to destroy Mystery, magecraft, and the Servant summoning system to allow themselves to finally die for good.
- Inside the story created by Scheherazade, we have Columbus as the Villain Protagonist.
- Big Damn Heroes: With the floating city collapsing and Astolfo's Hippogriff not being enough to save all the refugees, Helena appears after missing the entire adventure and uses her UFO to save everyone.
- Born as an Adult: The pirate ladies, Chinese torturers, and Amazons all reproduce this way, using sperm from captured men to somehow divide themselves into multiple copies.
- Debut Queue: Christopher Columbus is added to the summoning gacha after this story's completion. This chapter also debuts Caster of Nightless City, Scheherazade, Assassin of Nightless City, Wu Zetian, and Berserker of El Dorado, Penthesilea.
- Didn't See That Coming: Scheherazade picked multiple Servants from Chaldea for the roles she needed them to play, including Fergus for the chaos he'd sow in a land ruled by women. She intended to revert his age to a younger, more horny version before he became a proper king, but accidentally reverted him to his child (and far more innocent) form, throwing a wrench into her own plans.
- Double Standard: Abuse, Female on Male: Averted; the protagonist and their Servants can't help but react with horror, shock, and disgust at the abuse men receive in all three of the main kingdoms of Agartha, no matter how their leaders try to put a spin on it.
- Lady Land: All three nations in Agartha are ruled entirely by women, with men being second-class citizens at best and livestock at worst. Fergus wonders if this is the result of Scheherazade's own subconscious fears of men and equating them with death manifesting through her Noble Phantasm creating the Singularity in the first place.
- Light Is Not Good: The Nightless City, despite or because of Wu Zetian's efforts to enforce Light Is Good.
- Mêlée à Trois: The major factions within the Singularity are locked in battle with each other, focusing on trying to outplay the other.
- The Amazons, led by Berserker of El Dorado, control the western woods and are the most powerful overall. Due to being landlocked however, the pirates of Ys are able to attack them by the sea and the forces from the Nightless City send beasts out to hampfer their movements.
- The Pirates of Ys, led by Dahut, control the sea and overall are the weakest of the three main factions. They make up this with their usage of the sea allowing them strike quick and in areas the Amazon's can't properly expect.
- The Beasts and Torturers, led by Assassin of the Nightless City prefer to keep their city hidden to the north, sending out their beasts to go after anyone who isn't within a secure village.
- The Resistance, led by Rider of the Resistance, fights all three and want to liberate the men trapped by all three so they can escape and return home. Being the weakest of all factions, they mainly use guerrilla warfare to save as many men as they can and retreat to the south where they operate in a hidden valley of peace gardens.
- Never Found the Body: Dahut, Wu Zetian, and Helena Blavatsky all seem to die only to reappear later. Astolfo even lampshades they Never Found the Body.
- Not Himself: What happens to all of Chaldea's Servants that were taken by Phenex to fill roles in Scheherazade's stories. Drake becomes the pirate princess Dahut, Fergus is reverted to a child, and Heracles is mutated into the even more berserk Megalos.
- Sadly Mythtaken: In-universe, the Mission Control of Da Vinci and Holmes notice various inaccuracies in the presentation of each mythical city, eventually making them realize that the entire Singularity is more akin to a storybook than any other concept.
- To the Pain:
- The torturers in the Nightless City give a short summary of lingchi, the punishment their prospective victim will suffer for attempting to escape.
- Eventually happens to Phenex itself when Wu Zetian joins the battle, preventing it from rebirthing itself properly.