AN: For Guest-Questioner review. This KOS-MOS is in Episode I form, she was transported during the Woglinde trip. When I said she wasn't complete, let's say the archetype was her Alpha version, then her ver.1 body is the Beta stage, with the ver.3 being the official complete product (ver.4 is just a complete overhaul, with the black boxes blueprints and MIGHTY ERDE KAISER parts without Vector's authorization, so it doesn't count). Kinda like with the Unit-00, Unit-01 and Unit-02 of Eva, respectively.

And I'm leaning more on her fighting the Wyvern. Much more epic than bullying a pyromaniac bully though that could change.

In crossover settings, KOS-MOS was able to access her Transfer System armory, somehow. So she does have access to all her Episode I weapons except the X-Buster, though maybe she can create a weapon or two with Remnant technology…

Mmm, how would you think KOS-MOS and Penny meeting would go? Spoiler: Ruby will arrange it.

Just in case, I'm a little inexperienced/rusty in battle scenes, some tips, please?

With a single shot of Crescent Rose, Ruby beheaded a Beowolf while using the recoil to rotate herself and cut to shreds a pair more who tried to attack from her sides.

With another shot, she propelled herself to the skies, shooting and slicing all Grimm that jumped towards her like in a stylish action game air combo.

She extended her scythe into its War Scythe extended form and used it to impale two more that happened to be in her landing zone.

What followed was a short gymnastics dance in which the little reaper maneuvered around the scythe's pole to dodge the impulsive Grimm that come towards her as well as kick them.

Now with her scythe free and ready for more slicing, dicing and shooting, Ruby can't help but worry internally. While thanks to her uncle's teachings she was a decent fighter, she's only been training 2 years so she's still propense to errors.

Like forgetting to grab more ammo, especially when her fighting style is based around using the recoil of anti material rounds to augment her momentum, to compensate for her lack of physical strength. Okay, sure, she can carry and swing it like nothing but her melee attacks would obviously be weaker with her pipsqueak 13-year old body. She already had enough trouble enough to find the perfect balance with her 'baby'.

At least she had Aura and her Semblance, so as long as nothing went wrong…

As if tempting fate, an Ursa, hidden between the pack of Beowolves, slashed her when she least expected, making her fall and losing the grip on Crescent Rose.

And when she was about to recover, the same Ursa pinned her to the ground and pushed the weapon well outside Ruby's reach.

"NO!" she shouted in panic. The Ursa just tasted the delicious despair from the girl and prepared for the kill...

...Only to have its head pulverized by a bolt of plasma.

Ruby, who was covering herself, blinked and looked towards where the energy shot came from. Just to gawk.

Uncle Qrow prided himself in basing his weapon and fight style into those of his heroine, the Grimm Reaper, who was named after a being that brings death with its scythe. Ruby just being the last in following the trend.

However, Ruby's new companion cannot be compared to a Reaper.

She's a straight up Goddess ofDEATH.

The Rose And Her Battle Gynoid From Outer Space

Disappointment.

That's what's passing through KOS-MOS emotion emulator, not that it would show on her face, while launching a Grimm against another, killing both.

Those 'Grimm' are too fragile and stupid: not only would they die from a shot in the head or chest (like many other lifeforms) but they're so impulsive that they basically ignore basic animal instincts of survival and just throw themselves to their deaths.

Their only real advantage was their numbers. An ongoing analysis tells her that unarmed civilians or inexperienced and undergeared squadrons would fall quickly to the beasts, the latter due to attrition or incompetence.

Though there was the occasional Grimm with some tactical awareness that tries to catch her off guard, wait in the sidelines or simply run away. Sadly for them, those were given the most priority to exterminate.

No matter how insignificant it is, an enemy is an enemy.

She impales a Grimm with her bare hand, red eyes meeting. Ones brimming with hate, others without any shred of emotion. Both soulless. Only to break with a clean and brutal yanking that tore the monster from the chest to the side, cutting it in two. The corpse evaporating in black mist of unrecognizable composition.

Strangely enough, Gnosis comparisons came to her computerized thoughts. Both seemingly attack without known motives with brutality to humans, without an ounce of self-preservation.

Though that's only an analogy based upon this encounter, Gnosis exist mainly on Imaginary Number Space while Grimm are in the Real Number Space though with some anomalous effect on Imaginary. Though maybe there is a greater variety of more powerful Grimm in this planet, which she would require an extensive database if she were to be stranded on this world for extended periods of time, which is highly probable due to lack of U.M.N. access.

She would also need to know more about the other dangers of the planet, especially human ones. From what she's observing from Ruby, even while her technique needs numerous revisions, she's been capable of killing multiple hostiles, who possessed slightly above average human physical capabilities, with a combination of ranged and melee combat technique, at puberty and with a scythe, a tool considered cumbersome for fighting unless you straightened up the blade. If she were to mature and refine her fighting skills, she would probably become one of the greatest infantry-level enemies or allies for the Federation despite wielding such impractical weapon. There's also a huge possibility that this planet is training more of those fighters, due to the hostile fauna, so there could be warriors much more powerful, experienced and skilled, as well as numerous.

After kicking the head of one more of the dozens of Grimm she's been slaughtering, she takes note of a different Grimm, this one styled after a bear, pinning down Ruby and separating her from her weapon.

KOS-MOS gets out her pistol with inhuman speed and shoots the bear's head with improbable, freeing the girl.

Seeing as prolonging this encounter would be a waste of time, as well as energy and ammunition, the anti-Gnosis weapon summons her F-Scythe. The monomolecular, heated, high frequency, plasma-coated curved blade in a pole reaping through the Grimm pack and the surroundings like a heated knife through butter.

… Miyuki really overdid it here. Especially with a weapon KOS-MOS recently categorised as impractical, except for an apparent few. As well as previously noting she wouldn't need it for being absolutely overkill.

Oh, and it can shoot explosive energy waves from each swing, devastating the terrain and Grimm even more.

It seemed her preference for time efficiency made her go directly for the big arms for prey that weak.

In a minute and half, all the Grimm horde was cleared… as well as the trees and the grass… and the Earth…

… In her defense, environmental or property protection wasn't high in her directives. Not when there are terraforming nanomachines and highly advanced and cheap construction methods. In Federation space, that is.

Wonder how the inhabitants of this planet will take it.

Oh, there was already one. Nevermind.

At least, she successfully checked correctly various combat-live tests. Battle algorithms and weapon usage and transport? Checked. Nano-structural integrity? Checked. Battery life? Due to being an inferior test condenser and the usage of an energy demanding weapon, quite low. Higher capability energy source must be a priority. Or maybe a constant supply of food. And better energy expense calculations.

Returning to the local inhabitant, KOS-MOS observed her in a nearly catatonic state, nearly because while she showed some of the symptoms, the girl's brainwaves didn't show any abnormalities, so she was probably impressed.

Now that she observed her, the girl's eyes were fixed on the F-Scythe, which was yet to be unsummoned. Experimentally, KOS-MOS moved the high tech scythe to a side.

The girl's gaze followed it to the side.

KOS-MOS moved it to the other side.

Silver eyes continued to follow it to that side.

KOS-MOS proceeded to up and down the scythe hand, then to twirl it, moving it to different postures and finishing with launching it to the sky and catching it when it fell just like a graceful olympics gymnast.

And Ruby's eyes still continued to follow it through all the procedure.

Conclusion: the girl, Ruby, is fixated with scythes. Probably the technologically advanced ones.

It was only when the gynoid returned her own scythe to storage, the red hooded reaper had a different reaction.

"OH MY GOSH! THAT WAS SUPERMEGAHYPERAWESOME!"

...Which nearly overwhelmed KOS-MOS' auditory sensors weren't they designed with heavy warfare in mind. Then Ruby suddenly gained considerable speed and ended up close to KOS-MOS in a cloud of rose petals.

Wait, what?

"IcannotbelieveIwouldfindanotherHuntresswhichusedascythelikeUncleQrowwellItoouseonebutImnotstillconsideredoneImeananofficialoneImstillintrainingsowheredidyoutrainorbetteryetwheredidyougetthatjewelofascytheImayloveCrescentRosebutthatwasanotherleagueofitsown-"

KOS-MOS didn't pay attention to the child's rant, neither the fact she had incredibly powerful lungs. Instead, nearly all her processes were centered on the scientific impossibility that just happened in front of her eyes.

"What was that?"

"What?" The android's question managed to interrupt the hyperactive girl "What was what?"

"How did you manage to enter instant acceleration as well as… those roses?" Even with a monotone tone and body language, the mechanized maiden still managed to convey genuine confusion.

"Oh, that? That was just my Semblance." Ruby shrugged "Do you want to see it again?"

"It would be a pleasure. Just a moment." The android unfolded her D.S.S.S. visor "You may begin.

"Okay!" the girl happily said before accelerating in a petal cloud "How's that? Or that? Or this!" she continued to burst continuously, posing between each burst.

While Ruby was making her 'performance', KOS-MOS continued analysing her powers and if she could feel emotions instead of calculating them with her emotional emulator, she would feel bafflement.

While psychic powers exist and are extensively studied as well as technologically replicated, both generalised under the term Ether, there was one thing this girl's 'Semblance' could do that the former couldn't.

Manipulate the Imaginary Number Domain, repeat, manipulate the Imaginary Number Domain.

While too much is unknown about the Imaginary Domain, it's known that the Gnosis reside in it and are able to manipulate it, and consequently the Real Number Domain, with differing effects, resulting in Ether-like abilities from them. The only uses humanity found for the Imaginary Number Domain were those related to the U.M.N. such as communication and transportation and even those required technology to use them.

However, here was a girl barely entering her teens, using reality-bending powers thought only possible for the Gnosis, without an apparent Ether Drive, to run around at extremely high velocities and playing with them!

Apparently, some kind of unknown energy field, present in the IND (Imaginary Number Domain), surrounding the girl which manifests in the RND (Real Number Domain) each time she activates her ability. Not only that, but there's also some kind of pattern in her brain waves that appear at the same time as the energy field, so the cause may be psionic related. She needed more data. The possible repercussions of the existence of a psychic ability able to naturally interact with IND could be enormous and probably bring about a revolution in Ether and anti-Gnosis technology research.

"How does that work?" she felt compelled to ask.

"Uh? You don't know?" Ruby blinked "'Semblances are a more tangible manifestation of Aura' or at least they said in class."

Aura? Like the belief in a metaphysical energy that all living beings emit? "And what's precisely Aura?"

The girl just stared with open eyes and mouth, in disbelief "How could you not possibly know what Aura is?! Is the manifestation of the soul in every living being of Remnant and what allows Huntsmen and Huntresses to do all those cool things!"

"Actually, I had a guess for what Aura was. And I couldn't assuredly know due to not being a living being and not coming from Remnant, if that was the name of the planet."

The Rose And Her Battle Gynoid From Outer Space

If you just asked how many times Ruby's world shattered, you would hear "too many".

Not only she nearly died from a box that appeared from nowhere in the sky, but from it came a woman who not only knew about her and Crescent Rose while hidden (scaaary) but she also had Huntress-like skills with a laser gun that she would like to drool over but can also summon an ENERGY SHOOTING SCYTHE and use with the same level of skill as her superawesome Uncle Qrow, or possibly much more stronger than him!

However, that woman, Kosmos, she nearly forgot the name (it was on her headset and the box by the way), somehow didn't know some very obvious things for Huntsmen and Huntresses, despite looking like one.

Then she explains that she wasn't a living being and didn't come from Remnant. Adding in all that tech and her emotionless face, that must only mean…

"You're a robot. An ALIEN robot." Rby let out in awe, then snorted "You must be joking."

"I do not joke. I don't have a humor program installed." Kosmos deadpanned "And I was created by humans, though they and I aren't from this star system, so technically I'm an alien."

Ruby blinked, and tried to refute only to see the dead gaze of the android, which didn't express deception or anything really.

"I think I can offer further prove." Kosmos then proceeded to transform her arm into a cannon-like shape.

Wait, what?

"What was that?"

"Just an application of nanotechnology. Does your planet have achieved anything like that?

"I... read about Atlesian Knights able to turn their arms into weapons as well as cyborg prosthetics, but… I've never seen nothing like you did." Ruby let out, as if in rising realization "Does it work?"

Kosmos simply aimed the cannon into a surviving rock, charged it and shot. The resulting explosion simply disintegrated the rock into nothingness.

"Yes, it does work." said Kosmos, nodding apparently to herself.

Ruby blinked once, twice, then her face lit up like a Christmas tree.

"OH MY GOSH! YOU'RE AN ALIEN BATTLE ROBOT! IwonderhowmanyweaponsyouhavethereIveseenyoudesummonthatscythesomaybeyoudhaveateleportsystemthoughwithyourmorphingcapabilitiesyoucanjustsimplytransformintoweaponslikebladesIvealsoseenyouwithalasergunorwasitplasmaIthinklaserscanonlyburnwhileplasma-"

"Ruby."

"Yes, Kosmos?!"

Kosmos blinked "Please, I may have a more superior capacity than humans but that wouldn't help me in communicating with you if you still continue with random adrenaline bursts in your speech."

"Oh." Ruby's face reddened like her hood in embarrassment "Sorry. I don't have much experience with people, you know?"

"I noticed." Kosmos bluntly replied.

"Soooo, do you have some more questions of your own? Anything to know about our planet or something?"

"Yes, in fact, do you know where's the nearest spaceport?"

"Yes, in fact I-wait, a spacewhat?"

"Somehow, I was teleported against my will outside Federation space. My top priority is to return there ASAP." Kosmos took note of Ruby's troubled face "Is there a problem?"

"Kosmos, Remnant still hasn't achieved space travel."

Kosmos blinked "That's… troubling."

"Yeah..."

"Do you know if there are any research facilities that could possibly be the closest to reach spacefaring technology?"

"Uh? Well, Atlas has the best technology around, but why do you-oh." Ruby blinked in realization "I see what are you doing here, you're going to give them some of your awesome futuristic alien tech so they can construct you a spaceship, riiiiiiiiiiiight?"

"That's the idea yes."

Of course! Atlas is known for their great contribution to science in all of Remnant, of course they would have the brains for it, after all, it's where the CCT was created! Not to tell about access with resources just like the Schnee Dust Company, and, and…!

Ruby's eyes widened in alarm "Kosmos! You can't go there?"

"And why not?"

"Because-because… because that's where the biggest military in all four Kingdoms comes from! That is! And you're an alien superweapon, so they could probably hunt you down for being perceived as a threat, cut you open to see how you work or both!" Ruby breathed heavily. She can't let that awesome extraremnantian android to go straight to her death! Or the Atlesian soldiers to their deaths or both!

"..." Kosmos stood in silence for a few seconds "I calculate a probability of 87,9777956% of that scenario occurring, especially within a non-spacefaring civilization. And various of my technologies are classified. A discreet and indirect approach should be recommendable."

"Yeah! You do that!" Ruby exclaimed "Oh! Why don't you come to my house? We live in the outskirts of town so people won't notice."

"I accept the proposition, Ruby, I'm in your debt." Kosmos bowed.

"Oh come on! This isn't nothing hehehe." Ruby blushed "Mayyyyybe if you could show me some of your weapons, nothing too much secret, of course!"

"I consider the trade acceptable."

"Perfect! Now onwards! Our goal is the Xiao Long-Rose residence! For the space weapons!" Ruby shouted dramatically pointing towards her house.

Now, with Kosmos following her alongside her box, Ruby couldn't but help thinking.

"Best. Day. EVER!"

She just made friendly first contact with an alien robot with tons of cool technology (and weapons) waiting to be shared with the rest of the planet! As Remnant's self proclaimed representative, it's in her duty to take care of her guest and teach all about the wonders of Remnant! And the dangers, too. Wouldn't want Kosmos' people to find their secret weapon broken because of some Grimm or villain, thus sparking an invasion. Those almost always never go well for anyone…

… Maybe she should stop watching too many films. Does Kosmos like movies?

Now that she thinks about it, how will she explain this to Yang and Dad?

"Oh, darn it."

AN: well, that wasn't completely how I planned it at the beginning but it ended relatively decent. I initially thought of KOS-MOS using the F-G-Shots (the triple-barreled machine guns) but with all that Grimm Reaper talking, I decided, why not let her go full overkill? That was partly in character with KOS-MOS. And yes, I certainly overdid it with the F-Scythe description, due to being one of the most powerful weapons/techs in the first Xenosaga game, which was also designed by a weapon enthusiast from a time those sci fi weapon technologies could be realized.

Bet Miyuki and Ruby could be the best of friends.

Ruby being a sugar-addicted socially-awkward motormouth, especially when talking about Huntsmen/Huntresses and weapons? I enjoyed writing those parts.

And about the part with Kosmos instead of KOS-MOS? That was from Ruby's point of view and just met our sexy killing machine, she wouldn't have bothered learning the correct writing of KOS-MOS name/acronym.

For those well versed in the Xeno series, especially Saga: the Imaginary Number Domain refers to the Collective Consciousness of humanity, the plane where souls exist, in fact, the U.M.N., Unus Mundus Network, was named after a term Carl Jung used to describe the Universal Unconscious, which somehow worked as a huge but not that obvious foreshadowing.

The Gnosis also reside there for a reason, like the Grimm in RWBY, they're the Xeno answer to the Heartless. More specifically, they're angry, individualistic, anthrophobic (phobia to people) ghosts whose existence could cause an universal collapse. Oh, and that can turn people into more Gnosis or salt.

As for KOS-MOS analysis and rationalization of Aura and Semblances, you should have realized now that because those are the manifestations of the soul, they would be detected in the IND. Take also note that some of the strongest Xenosaga villains, the Testaments and possibly T-elos, are so goddamnly powerful due to being able to manipulate the IND and with it the RND, essentially turning into minor reality warpers. Which would made sense when applied to the physics-breaking Aura and Semblances though not at the scale that group is able to.

Welp, now next time would be Taiyang's, and possibly Yang too, reactions to KOS-MOS. Hehehe.