The protagonist ends up in a pseudo parallel world in their sleep, where things are a bit... off. While wandering, they run into vagabond swordswoman Miyamoto Musashi and decide to travel with her. Then they run into Inshun Hozoin, a little girl and her baby brother, and a horde of ravenous monsters. Things really, really, escalate from there.
Prima Cantica: Purgatorio
Seconda Cantica: Inferno
Terza Cantica: Paraiso
Quarta Cantica: Kalasutra Hell
Ultima Cantica: The Stage of Carnage, Onriedo
See You Again Someday, Flower at the Apex of Heaven
- Alternate Universe: Up till now, the game has had the protagonist travel to distant parts of the timeline to fix human history. This one takes place in a parallel world.
- Anti-Villain: Sasaki Kojirou is only a villain because he's on Amakusa's side. He never does anything villainous nor does he enjoys the violence Amakusa's side inflicts, he's simply there to repay Amakusa saving his life.
- And Then What?: After beating Raikou and Shuten, Musashi muses to herself she's actually close to completing her swordsmanship but is anxious as a result. She reveals her determination to complete her swordsmanship was simply to surpass her father even happy to continuously traveling to other worlds if she can get stronger. But now that her goal is within sight, something she admits she never though was possible, she's honestly confused on what to do afterwards since she no longer has a home nor someone to settle down with.
- Back from the Dead: At the end of Shimousa, Musashi dies after winning her fated duel with Kojirou. But due to her achievements, she becomes a servant and makes a contact with the protagonist.
- Badass Creed: Since Shirou Emiya has become a Demi-Servant, his elegy has been updated to match the mindset of the Heroic Spirit that controls him.Though I am not Jubei, the invincible swordmaster. Though I am not Hanzo, the great spymaster. Though I am not Abe-no-Seimei, like your so-called Caster. Though I am nothing more than a swordsmith, why was it I that was summoned? You could never figure it out, and so you have lost. I once sought to forge the ultimate blade. Not one that cuts through flesh, bone, or the living. I sought a blade that terminates enmity...A blade that severs bonds, severs certainty, severs karma. That is to say, to be free of one's fate. Uncountable years of toil to reach this place. Forging thousands of swords to create a barrow of blades. Many paths, converge here. Enduring desires, flow here. Unjust deaths, gather here. My whole life has been for this single swing. The heart of the blade is here! Accept this blow from my Tsumukari Muramasa!!!
- Battle Amongst the Flames: The final battle of the chapter is a one on one duel between Musashi and the real Sasaki Kojirou in a castle set on fire.
- Big Bad: A still living Amakusa Shirou Tokisada who survived his Shimabara Rebellion and then spent 20 years traveling throughout alternative worlds and grows embittered that no matter where he went, his rebellion failed and Japanese Christians were slaughtered.
- Blood Knight: Yagyu Munenori to a shocking degree when he finally reveals his true identity to the heroes at the climax. He reveals the reason he's helping Amakusa potentially destroy reality is for a true death match against Musashi.
- Brainwashed and Crazy:
- All of the Seven Heroic Spirit Swordmasters barring Caster of Limbo, Saber of Empireo and Berserker are this, but several stand out:
- The protagonist and Musashi first meet Inshun as an affable servant who spent two days killing all the evil spirits he could find. He is forced to fight off the enemy so the protagonist, Musashi can protect the two children that was with them and is transformed into a bloodthirsty enemy who revels in slaughtering women and children wholesale as a result.
- Assassin of Paraíso is shown to be relatively kept together barring a few moments where she loses her temper despite the Curse of Annihilation on her mind at first. However, she fully falls into this when her cursed blood is fully awakened against her will, where-upon she becoming a ranting madwoman determined to complete her mission that splits between desiring to kill the heroes and bemoaning her ancestral curse and how everything she did to be free of it was All for Nothing.
- Carnival of Killers: The main villains are the Seven Heroic Spirit Swordmasters which are 7 heroic spirits that were empowered and corrupted by their summoner and the Caster of Limbo.
- The Corruption: The Curse of Annihilation that Caster of Limbo casts on the other six Heroic Spirit Swordsmen make them bloodthirsty monsters that desire the death of everything living. It turned Inshun from a noble monk into a psychopath that only wanted to kill everyone in his way for fun, and Assassin of Paraíso gets a double-dosage of corruption courtesy of her Orochi-cursed blood.
- Debut Queue: Yagyu Munenori and Kato Danzo are added to the summoning gacha after completing the episode.
- Deuteragonist: Musashi is your main companion and has an arc of reaching void throughout the chapter.
- Doomed Moral Victor: Mixed with In Spite of a Nail as well. Amakusa hopped across realities to see if his rebellion actually succeeded. And in nary a one it did not. He didn't take it well.
- Duel to the Death: Every single duel Musashi participates in with the antagonistic Servants ends this way.
- Evil Counterpart: Musashi has two in this chapter.
- Yagyu Munenori: They are both still living humans that can battle and kill heroic spirits, are considered among the best swordsmen that come from Japan and enjoy duels with skilled opponents. But while Musashi understands there is a time and place for duels and can even be disappointed with herself for her automatic response to danger to prepare for a fight instead of protect those weaker than her, Munenori is working with Amakusa and the Caster of Limbo to destroy not only his world but all the various parallel worlds just to have a true death match with Musashi once again.
- Amakusa Shirou Tokisada: They are both living humans that can travel the multiverse and are strong enough to fight heroic spirits. But while Amakusa went mad from his 20 years traveling between the dimensions and wants to destroy all of reality as a result, Musashi despite spending an untold number of years traveling to various worlds is still chipper and kind, unwilling to let the innocent be harmed.
- Eye Scream: Musashi loses one of her eyes when Danzo self-destructs.
- Eyepatch of Power: After losing her eye, Musashi uses one of her katana's tsuba as a makeshift eyepatch. This is supposed to be a reference to Yagyu Jubei's own signutare Eyepatch of Power since Musashi is playing the role of Juubei in this Samurai Reincarnation reenactment. Jubei's father Dajima-no-Kami lampshades their similarities.
- The entire chapter turns out to be a prototype Lostbelt (though it's called a Missing Belt by Limbo) caused by Caster Of Limbo, who takes orders from a being he calls God. Earlier on, Amakusa comments that he can see the "Roots of Fantasy" descending, a phrase that would be used by Wodime in the Cosmos in the Lostbelt prologue.
- For the story itself, Musashi notes that Munenori actually doesn't value human life that much. Danzo explicitly states that she works under his orders. Is it any wonder that the final Heroic Spirit Swordsman is Munenori himself?
- Gameplay and Story Integration: At first the protagonist can only use Musashi and for a brief time Inshun due to not being connected to Chaldea. But after meeting Inshun, they can call upon their servants in battle again but they don't seem to be with them, Kotaro briefly brings this up, comparing Servants only appearing in battle to shadows that can only manifest for a brief time. Also, this is why unlike the Mash that travels with you in regular battles runs away after being defeated, this one fades away like any other servant.
- Gameplay and Story Segregation: While Musashi does join Chaldea at the end of the Singularity, whether or not the Player actually gets her is another matter entirely.
- Good Feels Good: Musashi admits that it's not in her nature to be a hero and if it wasn't for the protagonist's guidance she would ignored the monsters. But she admits fighting for what was right for once was fun and far more fulfilling. In her last moments, she thinks she was so grateful to have met the protagonist.
- Hope Spot: After defeating Berserker and Rider and rescuing Onui and Tasuke safely, things are looking up with the heroes even enjoying a new day and about to eat breakfast...and then Caster of Limbo and Amakusa kick the final stage of their plan into high-gear using the sacrifices and the souls of five of the seven fallen Swordsmasters, resulting in countless people turning into monsters as the blood moon permanently blankets Shimousa.
- Madden Into Misanthropy: Big Bad Amakusa admits he's insane after traveling through the multiverse and seeing that no matter where he went, his rebellion was doomed to fail. In the Psuedo-Parallel World, he openly laughs when people are slaughtered and plans on destroying the multiverse in his rage.
- That Man Is Dead: After Inshun falls to the Curse of Annihilation, the Lancer Purgatorio and even Musashi state that Inshun is dead due to how deeply the curse corrupted his personality. Generally all the Seven Heroic Spirit Swordsmen say the Heroic Servant they were are dead and they are simply the remains.
- Mistaken for Romance: Quite a few characters seem to think Kotaro and Danzo are attracted to each other due to Kotaro being flustered around her and her focus on him, but in actuality Kotaro thinks of Danzo as his mother.
- Mole in Charge: Yagyu Munenori works as a strategist for the Tokugawa against the Seven Heroic Spirit Swordsmen that he's part of, he can realize the irony of the situation.
- Morality Chain: At the end of the Shimousa, Musashi admits that it was because of the protagonist, Onui and Tasuke that she fought them head on instead of running away. She admits it was the protagonist's bravery and morals that guided her to fight for what was right.
- Mythology Gag: Sasaki Kojirou stopping Musashi from escaping using the stairs mirrors his role in Fate/stay night where he stopped Altria from entering Ryuudou Temple by defending the stairs.
- Shirou Emiya is once again chosen to be a Counter-Guardian, but it's not exactly like in that other story.
- The Power of Hate: Tomoe as Archer Inferno can only remember her hatred when her husband, Yoshinaka was betrayed and killed. Tomoe even questions why she can only feel hatred. After being defeated, she remembered that in life she was able to get past her hatred when she remembered Yoshinaka wanted her to live and even lived a long life and died peacefully.
- The Rival: The moment Musashi and Kojirou meet, they instantly know who they are and that they must fight to the death, showing that their rivalry is their destiny. In fact the elderly male Musashi refuses to die because he hasn't had his legendary duel with Kojirou yet.
- Running Gag: A Lancer is still unlucky, this time it's Inshun, who not only is corrupted by Caster of Limbo and is the first of the Seven Corrupted Servants to fall.
- Shout-Out: After the corrupted Inshun gets his head lopped off and nonchalantly puts it back on, Musashi declares she's not fighting an opponent "who won't die even if you kill him!"
- Suspiciously Specific Denial: Downplayed. Danzo is present and futilely protesting when Shuten and Raikou decide to destroy the entire province of Sagami. When the other protagonists hear this latest shocking news, she feels the need to specify that she absolutely hadn't known either.
- Tagalong Kid: At the start of the Pseudo-Parallel World, the protagonist and Musashi befriend Onui and her little brother Tasuke. They continue to tag along with the protagonists even after the protagonists have taken them back to their grandfather, Muramasa.
- Theme Music Power-Up: A Japanese instrument version of "Emiya", "Unoriginated (Unsourced) Blade Works" makes its debut here.
- Took a Level in Badass:
- At the start of the Pseudo-Parallel World, Musashi is under-leveled and missing her third skill but as she continues to fight the Seven Heroic Spirit Swordsmen, she grows stronger.
- Kotaro throughout the Pseudo-Parallel World grows stronger, first by gathering the kunai of Assassin of Paraíso and later on taking Danzo's remaining magic energy after she explodes. He is then shown with his third ascension sprite and is asserted to be the ultimate ninja.
- Whole Plot Reference: To the historical fantasy novel Samurai Reincarnation, with famous Japanese figures being resurrected as zombies by Amakusa Shirou and it being up to one samurainote to bring the villains down and restore peace.
- Wouldn't Hurt a Child: Contrary to her companions, Raikou's motherly instincts are so strong that she refuses to harm children despite the Curse of Annihilation making her loathe the world and sadistically slaughter any adult in her way.