Nasuverse Fate/Moonlight [FSN/SM x-over idea]


Lazy Bastard...

I don't usually do this but I had an idea. An idea that I want to see if it has some potential traction. An idea of a potential cross-over between Sailor Moon and Fate/Stay Night that would have Shirou be Mamoru Chiba before the Fuyuki Fire and potentially the consequences of a Tuxedo Mask with an ability in magecraft as well as having Sailor Moon deal with a scenario where her soul mate is in love with someone else.

For the sake of everyone, the universe is an AU Type-MOON-verse and the base for FSN is the true end of Unlimited Blade Works while the base for Sailor Moon is the first anime.

Here's what I've outlined so far, your thoughts and ideas would be greatly appreciated. As an aside it's open for takers.


- Opens up to a scene long forgotten near the final weeks of the Moon Kingdom. It's Endimiyon being dragged aside by Serenity away from the moon cats to spend some alone time together. Probably some sappy teen love stuff here that has extra meaning due to what will happen in the near future. Endimiyon voices his concerns/suspicions to Serenity. Endimiyon is concerned about Lady Beryl, but Serenity assures him that no matter what happens she will be by his side for the worst. Maybe have Endimiyon tease Serenity a bit asking

if that was a marriage proposal with Serenity asking if he wants it to be.

-Endimiyon answers with a kiss and Shirou wakes up in a haze. When he wakes up it's basically that F/HA scene edited to include his thoughts on the dream. While he has trouble remembering them, it's clear that at this point the dreams are becoming a bit clearer and that he's been having them for weeks. Rin and Shirou have pleasant early morning talk before Rin pick up on something off about Shirou and assumes he had that dream again with Shirou's confirmation and his admission that he's starting to remember more now Rin decides that it's time to start investigating into this maybe even tease him a bit about dreaming of girls besides her.

...dirty cheater

The duo leave Shirou's compound for school with some small talk as well as Rin discussing having put in her application for the Magician's Association. As they make their way to school they run into a group of boy harassing a young teenage girl. Shirou goes to save her, reviving some praise from the girl who has a cat in her arms. The girl runs off in a panic after crying out she's late, to Shirou and Rin's amusement.

Prologue #2:

-Opens up to a dream of when Serenity first met Endimiyon. Usagi awakens from the dream, idly dissapointed as it was getting to a good part before her mother shouts out that she's going to be late if she doesn't get dressed now. This prologue is mostly told from her point of view detailing the differences in her thought process until she runs into a group of boy picking on a cat. She tries to scare them off but the boys aren't having it, leading her to be saved by an incredibly handsome older boy with red hair and gold eyes.

Ch. 1:

-Begins from the combined prologues of Shirou and Usagi's first meeting. It then follows Shirou and Rin at school as the student body is forced to get used to the new satus quot of the School's Idol being the School Janitor's girlfriend. On the flip side, Usagi is dealing with school while fantasizing about Shirou. Usagi's portions are mostly a replay of Sailor Moon Episode one.

-After School Shirou and Rin are dealing with figuring out how to get Taiga to deal with Rin's subtle attempts to move into Shirou's home. They also engage in a bit of small talk as it involves Sakura and his strange dreams. During the conversation, Shirou and Rin doze off in each others arms. It's at this point, Shirou mysteriously dissapears.

-Chapter ends with the fight between Sailor Moon and the youma who has possessed Naru's mom.

Ch. 2:

-Chapter opens with Usagi remembering her first fight with the Naru's Mom youma. She still freaks out over the encounter but has fantasies about the mysterious man who saved her, Tuxedo Mask. Luna tries to get her to focus on her mission in futility, all the while wondering what agenda that mysterious man may have in store for them.

-Meanwhile, Shirou awakens on the couch back at his home with no clue on how he got there. He finds Rin nearby having watched over him through the night. As Rin wakes up he's pelted with questions on where the hell he dissapeared to and what he was wearing. He's confused as she informs him that whatever he was wearing was teeming with magical energy the likes she had never seen. As she calms down, Rin vows to get to the bottom of the new mystery surrounding Shirou.

-A few days pass and Rin is irritated as she's nowhere close to figuring out what the deal with Shirou is. She hypothesizes that it may have something to do with Shirou's strange dreams but that's all it can be atm. She's broken out of her thoughts as she feels the powerful magic once again, and a loud thump out in Shirou's courtyard. She goes out and catches a brief glimpse of Shirou dressed as Tuxedo Mask before he vanishes from sight. Rin is dumbfounded as the magical energy seems to dissipate like Shirou did.

-Cannon Youma Battle #2 happens here, no major changes.

-Cannon hint at Dark Kingdom evil.

Tuxedo Mask returns to the Emiya compound, his outfit fading once more and leaving Shirou unconscious. Rin catches him as he falls, a from on her face as her determination to get to the truth grows.

Ch. 3

-Chapter opens with a flashback to Endimiyon holding a conversation with Jadeite over the events of the day and any potential dealings that need to be addressed in the Earth Kingdom at the time. As it passes the conversation turns to talk over Serenity, and their burgeoning relationship. Jadeite briefly goes over the political benefits of the relationship before they talk about how he feels for her. Highlighting the friendship between the two.

-Present day, Shirou is sitting his living room across from Rin. Rin has convinced him to allow her to hypnotize him to see if that will be able to understand why he's going off in a magical outfit at nights. Rin teases that now would be a good time to tell her any secrets he's been holding lest she gets him to confess while under hypnosis. Shirou tells her point blank that he trusts her completely to not take advantage of him like that. Rin blushes deeply and quickly puts Shirou under hypnosis. As she does Shirou awakens dazed and confused, asking for Sailor Moon. Rin tries to get Shirou under control but he's getting more frantic demanding for Sailor Moon. Rin breaks the hypnosis and Shirou awakens confused. Rin comforts Shirou and is comforted by the information that she now has. A mage(?) named Sailor Moon...

-Sailor Moon side prepares to deal with the introduction of Sailor Mercury. Not much changes yet.

-Pre-youma battle Rin has Shirou ingest a magic gem that allows her to see through his eyes. She silently note the similarities to Archer but doesn't dwell on it due to the seriousness of the situation. Time comes to deal with Youma, not many changes but Rin is able to follow Shirou/TM and watch the battle. She is dumbfounded by what she sees. She becomes aware that she needs to deal with the mystery at hand but also vows to tease Shirou about this relentlessly.

Also she was wrong about Sailor Moon. She's an even WORSE mage than she thought.


KING (In Land of Blind)
Staff member
So let's just go ahead and talk about the first thing everyone complains about with a Nasuverse cross, and then get into setting-specific stuff, and then talk about details.

In Sailor Moon, a "Sailor Senshi" is a human incarnation of a Planet's Star Seed. As the avatar of a planet, they have superhuman physical powers, vast magic, and eventually a Castle or something I guess. In the Nasuverse, each Planet in the solar system possesses a Planetary Will and native organisms. If one of those organisms kills and kills and kills until it is the only member of it's species, until it is unquestionably and undoubtedly the strongest life-form on the world, it synchronizes with the Planetary Will and becomes an Aristotles, or a Type. Among those, several were mentioned in Notes (the Types of Venus, Jupiter, and Saturn) while the Types of Mercury and especially the Moon have bigger roles in other materials. (Earth's Moon has a Type as a special case. As fanon, I assume it has to do with the Thea Impact Hypothesis.)

How can we reconcile those?

Simple: a "Senshi" is a human who accepted something like the Familiar Contract of a Type.

In this case, keep the "excessive frilliness" and girliness of the Senshi Transformation, but replace the "elemental theme" with shadows of the concomitant Aristotles. Rather than spraying foam and water at enemies, for example, Ami just instantly murders them with unfair power.

The Types and what that means for the Senshi
Mercury: Overwhelmingly, the most powerful Type; recognized as the strongest organism in our solar system. Crystalline spines and spires with a spider-like feel. Also, the ability to absorb the abilities of those it defeats. Basically, as soon as Ami shows up, the fight is over, she is the One Punch Man, the end.

Venus: The Angel, V/V. Seduced and fell in love with a very Kiritsugu-like character, the last human (Everybody else was a genegenieered transhuman cyborg that fundamentally didn't count as a "human" any more), who was simply called Gun God, after his magic rifle, the Black Barrel. She was something like a ghost in Notes, so her real powers aren't known, but the A-Rays (a kind of transhuman) of the "Angel" type used their wings not for flight, but as collecting dishes to charge up their Lazor Beamus.

Earth: Gaia. Accepting a Contract with the World makes one into a Counter Guardian after death; the Heroic Spirit EMIYA instead made a similar contract with the Will of Humanity, Alaya, and became a Guardian that way. As such, compared to a Senshi Contractor, Shirou might experience "friction" and operate more like a Guard rather than a Senshi: made into a mindless killer, and given plenty of magical power to complete their mission, which is always "just annihilate everything in the area".

Moon: The Crimson Moon, Brunstead, the one who founded the True Ancestors of the Vampire Race. Killed by the Wizard Marshal Zelretch during a duel about eight centuries ago. As a contracted familiar of the Moon, Sailor Moon would receive vampiric powers such as blood-sucking to sustain her existence and reversal of injury, hypnotic eyes, and claws; also she is probably something like a cousin to Bruenstead's clonal daughters, Altrouge and Arcruid. So the Dead Apostle Ancestors - super-vampires based on Brunstead's magical teachings - will probably want to drag her into their factional dispute over which princess should succeed the throne of Millenium Castle Brunstead, the Marble Phantasm of the Moon. Or you could swing her as the reincarnation of the dead daughter of Brunstead and his human Senshi, Serenity the First? I dunno how much Tsukihime you want to drag in.

Mars: Not described.

Jupiter: A gaint cloud of black particles that resembled a humanoid dozens of kilometers tall. Possessed a "core", which ran out of control and incinerated a continent after it was killed by Ado Edem. Saturn: A cross a thousand meters long. Big and shiny, shot cross-shaped beams. Killed by Ado Edem.

Uranus and Neptune: Not described, but they worked together in Notes, so that matches Sailor Moon at least.

Pluto: It's dead body was responsible for the "Blood Sky" setting of Notes. Killed by a Genuine Wizard called the Six Sisters, because she had six bodies simultaneously.

Serenity / Endymion stuff in Backstory
So there's a star-crossed lover story in Sailor Moon: 10,000 years ago, the princess of the Silver Moon Kingdom loved the Prince of Earth, but their respective parents forbid them from loving each other, because the Earth Kingdom was suspicious of and hostile to the Silver Millennium Space Civilization.

10,000 years ago in the Nasuverse was the Age of Legends, when the King of Kings ruled over the whole world as an absolute Tyrant, created by the Gods to reign in humans, but who instead championed humans against them. So I guess that means that Prince Endymion's dad was Gilgamesh.

I really like the sound of that, so I think you should run with that.

Gilgamesh has no use for bastards who ran off and swore fealty to other planets, also he fucking hated Brunstead, no way he's gonna share a grandkid with that bloodsucking asshole.

If I was you I might swing it that it's only because of Endymion's permission as "Earth's contractor" that Brunstead was invited to transit onto Gaia, which makes Shirou's past life indirectly responsible for basically all the vampires. That would be a rad thing to dump on his shoulders.

Specific Notes on what you've got plotted
First off, Sailor Moon happens in the Minato ward in Tokyo, while Fuyuki is understood to be an expy of Kobe City, which is over next to Kyoto. That means it would a couple hours by bullet train for either of Shirou and Usagi to be in the others' neighborhood. You should think about addressing that, even if it's just on the level that Shirou is visiting Tokyo for some reason. (Maybe Rin dragged him along when Waver Velvet insisted that her interview be in Akibahara, and Usagi was visiting the electronic city as a game otaku? Well, that brings Professor El-Melloi II into the story right away though).

Every time I see the hero introduced to the heroine by smacking around a bunch of one-note bully scrubs, I sneeze. Well, I realize that scene was Sailor Moon canon, but I would get away from it anyway.

Plus Shirou is extremely sensitive to paranatural phenomena; he can literally smell it a mile away, since he interprets prana as smells. He would confidently know that the Moon Cats were magical the instant he could detect them, and he could probably determine they were "otherworldly" quite quickly as well.

As a user of Gem Magecraft, the theme-naming of the Dark Kingdom is going to be screamingly obvious to Rin.

As a general rule, anyone includes the words "and then it happened just like in canon" in a plot outline for their fanfiction:
That is a bad fanfiction.

I would encourage you to diverge as hard as you can, as early as you can, and really hare off into the woods. For example, since the Nasuverse is a Wainscott setting with lots of people invested in enforcing the Masquerade, somebody like the Blue is going to come down on the Dark Kingdom like a pile of bricks if their Youma Attacks are as obvious as in canon. I dunno they could win against magical nuclear bombs, especially if she breaks into their pocket dimension and doesn't need to worry about holding back at all.

Wait, what about the Dark Kingdom anyway?
I haven't even considered where Metallia came from, why she/it had brainwashed Beryl and the Generals, and what it means that Shirou will consider those four guys as friends from a Past Life. He is going to be putting serious efforts into saving all five of them once it becomes apparent that they were magically forced to work for the shadowy actual bad guy.

What are youma, too? Are they like, familiars created by injecting Metallia's prana into something?

In conclusion, my advice basically boils down to three fundamental points under the stuff I just threw out there.
Put some thought into how you're going to mesh together...
1) ...the magical powers & cosmology of each setting. (Sailor Senshi are Types' Familiars.)
2) ...the historical events of the Moon Kingdom and the Age of Legends. (Gilgamesh is Endymion's dad!)
3) ...the current events of Sailor Moon and the Moonlit World. (Have the Dark Kingdom respect the Masquerade.)

That's about it, I think.


Well-Known Member
daniel_gudman said:
Everybody else was a genegenieered transhuman cyborg that fundamentally didn't count as a "human" any more
That's not really true. The original humans who can't survive in grain environments are technically called Last Seeds as versus Liners, not humans as versus Liners. Both are still basically humans, the Liners are just those adapted to not be poisoned by grain. The Ether Liners are a different thing, and are basically to Liners what magus are to regular humans before the apocalypse in that they have more to them (Knight Arms as versus Circuits) that give them special abilities. Liners don't have special abilities or function, they're just humans able to not die to grain.

It's more like Liners are technically A-Rays in that they're a post world adaption, but they're also still humans, so they fall under both categories while Last Seed and the created A-Rays only fall under one of them.
How you handle the past basically depends on what you want the story to resemble tonally. Do you want it to be dark like Nasu, or positive like SM? I like the idea of Gil as TM's dad, but he's a brutal tyrant so you risk ending up making the Dark Kingdom into something more like freedom fighters if you oppose him. Also, and perhaps more pressingly: hard to buy Metallia and Co taking him down either way.

As for the moon: CM and Serenity cannot coexist in their basic forms. Period. CM is King Shit, and we're supposed to believe that the Moon Kingdom was a utopia. What you COULD do that I think would be interesting is have him be a MK footsoldier who, during the collapse, fought so long and so hard that when the dust settled, he was alone on the moon, warped by bloodshed and black magic into the CM we know. Would explain him declaring himself king of the moon and why he wants to leave and grind Earth into dust.