Disclaimer: I do not own RWBY, it is the sole intellectual property of Monty Oum and of Rooster Teeth.
Nor do I own Fate and other elements of the extended Nasuverse, they are the sole intellectual properties of Kinoko Nasu and of Type-Moon.
However, I do set claim to any original characters outside of the juridiction of either companies. (For the lot of good it'll do me...)
Prologue:
Jaune Arc was beginning his first day as a Huntsman-in-training in the prestigious Beacon Academy. Now that in itself wasn't that much to write about, even if Beacon was the premier Huntsman academy of Remnant, but what distinguished Jaune from the rest of his fellow trainees was something that he had over any other people on the world of Remnant.
Jaune could use Magecraft.
Magecraft was a branch of thaumaturgy that aims to replicate the various miracles of True Magic through means reproducible with science, or at least that's what his teacher of a handful of years, Shirou Emiya, a Magecraft User from another world who found his way on Remnant by accident with something called the Kaleidoscope, told him back then all those years ago.
Jaune met his Magecraft teacher by happenstance. And after a misadventure involving some Grimm, the then young boy on the cusp of teenage hood aspiring to one day become a Huntsman, managed to convince the outerworlder to teach him what he concidered at the time as magic.
Of course back then Jaune had no idea what Aura or Semblances were, and thus when Shirou made use of his Magecraft to project various weapons, and use a reinforcement spell on himself to defeat the Ursa Major alongside the various normal Ursai and Beowolves that threatened the both of them, Jaune instantly likened the abilities that Shirou displayed as magic and was quick to tell as such to the Magecraft user.
After quickly figuring out that he clearly wasn't on Earth anymore by the presence of these Phantasmal Beast that the young Jaune called Grimm, the appearance of Remnant's broken moon, and by the fact that he clearly couldn't feel the Earth's spirit of Gaia rejecting his projections, Shirou wasn't that much worried about some random kid witnessing Magecraft. And after a few moments of reflection he decided that he'd ask one specific question and that whatever answers he'd get would make him agree or not.
"Why do you want to learn Magecraft?"
The boy didn't had to think too much to answer as his eyes instantly lit up at the question.
"Because I want to be a hero!"
This was aplenty for Shirou to teach the boy the amount of Magecraft he knew and learned at the Clock Tower, a sort of magic school as he would eventually roughly explain to his student, and to tell him about where he came from, Earth, the Kaleidoscope, Magi, Phantasmal Beasts, and every tidbits of information he knew about the Moonlit World in the time he would have with the boy and in this world until his girlfriend, one Rin Tohsaka, would come to bring him back home according to a message he received earlier in the day from her before meeting Jaune.
In addition to being his girlfriend, she was first and foremost one of his fellow students at the Clock Tower, a genius of her own and the one responsible to have accidentally sent him on Remnant when she attempted to make a Jeweled Sword of Zelretch, named after the master of his girlfriend and the aforementioned Kaleidoscope.
In the beginning the greater half of all that his teacher spoke of flew over Jaune's head, but as the time passed, and that days changed into weeks, weeks into months, and months into years, Jaune slowly but steadily began to learn Magecraft and all which it encompassed.
Though at the very beginning of Shirou's teachings, the now second rate Magus whose magical knowledge greatly increased thanks to his studies at the Clock Tower and with the help of his girlfriend, very quickly found out that while using the Structural Analysis spell to try to find and activate any potential Magical Circuits within Jaune's body that his student, and really any other Remnantians, weren't quite made the same as any other humans from Earth.
The people of Remnant, while outwardly looking very much similar in any ways, shapes and forms as any humans from Earth, weren't quite the same on the molecular level.
Indeed, the bodies of the humans of Remnant were made at base level of a substance commonly found on the planet called Dust.
The substance, when found in humans, replicated the basic makeup and biology of Earth's human to an uncanny level. Replicating molecular, cellular and organical processes at perfection. Shirou wagered that if he was to take a blood sample from Jaune and run it through a mundane DNA analyser from Earth that the computer wouldn't be able to distinguish the difference.
It was almost as if some divine being saw Earth's humans, got curious about how they worked, and that through some alchemical processes made homunculi using Dust as the primary material to try and seed sapient life on the planet.
Shirou believed that he wasn't so far from the truth.
Because no matter how you looked at it, the humans of Remnant couldn't have suddenly evolved from such an unstable substance without a direct outside influence, especially considering that the animals around them, no matter if they were bugs, fishes, amphibians, reptiles or mammals, they were all made the same as their Earth counterparts. Without Dust.
But luckily, Jaune's body makeup didn't interfere with his students abilities to learn Magecraft. As it turned out, Jaune's body was exceptionally well attuned to magic. Shirou could detect a wellspring of Od coming from Jaune's life force within his body and his soul had stores of dormant Magic Circuits.
Shirou yet again hypothesized that Remnantians were especially more attuned to magic thanks to their bodies' origins.
Along the way, Shirou couldn't help but to fear for his student's well being in such a Death World teeming with the Creatures of Grimm, and thus decided to offer him a very special gift in the form of a legendary sheath.
Because Remnant visibly lacked a world spirit that rejected anything supernatural, the Magecraft user made a copy of Avalon, the eternal utopia and sheath of the Once-and-Future-king of another world that he held within himself, which could stay projected indefinitely within the world of Remnant and thus could be implemented within Jaune's body, offering him enhanced healing effects.
Of course, all of this was before either of them could learn about the wonders of Aura.
Some time in the midst of his teachings, Shirou wanted to learn more about the world he found himself in. Thus, after he faced the Ursa Major and the other Grimm, promised Jaune to teach him Magecraft and brought him safely back home, and managed to secure some lodgings in Jaune's village of Domremy after being accepted as a blacksmith, one of his specialities, Shirou decided to learn more about the world of Remnant.
And suffice to say that after what he learned he quickly noticed that his student was severely lacking knowledge about the world he inhabited.
Oh this wasn't fault on Jaune's part. The young boy that grew even more each passing day had a thirst for knowledge, especially anything that could be useful for him as a Huntsman. No what Shirou discovered was that the boy's own parents were purposely hiding any kind and manner of information about Huntsmen and their trade.
It wasn't necessary to point out how much the Magecraft user was disappointed with the parents of such a brilliant and promising young man.
But fortunately Shirou was quick to understand that the Arc parents weren't doing this out of spite or any negative sentiment. He found out that they hid everything Huntsmen related to Jaune because they feared for their little boy, the only male heir out of eight siblings of the Arc legacy.
He discovered that his new and very first student had quite the bloodline. Jaune Arc was the descendent of an ancient and prestigious family of Huntsmen and heroes. The Arcs were battling against the forces of darkness, be they Grimm or otherwise, from as long as the world could remember.
Hence why his family wanted to hide anything Huntsmen related, they feared that their only son would become another fallen in a long line of deceased heroes just to uphold the family legacy.
Fortunately after some convincing and assurances that he would teach everything possible to keep Jaune safe and healthy and, most importantly of all, abilities that would give him an edge against the forces of darkness on Remnant by showcasing his Magecraft to their shock, Shirou managed to convince Jaune's parents to let him learn anything that could make him a better Huntsman.
Thus Jaune was introduced to the concept of Aura and Semblances, was given the family's heirloom, Crocea Mors, and even managed to unlock his Aura by himself when experimenting with his Magic Circuits.
Which led Shirou to validate a theory about a hidden or forgotten fact of the world of Remnant that he suspected from a certain time by now. The people of Remnant used to have magic. True Magic.
Jaune's teacher quickly understood that Aura, and by extention Semblances, were literal remnants of an age were the world used to have magic. He hypothesized to his student that at one point there was an era on Remnant similar to the Age of Gods on Earth where magic and the supernatural were more common. Which would explain the Dust origins of Remnant's mankind. And that after some kind of as of yet unknown event the magic of Remnant diminished until there was only Aura and Semblances left. Though he couldn't still explain the existence of the Grimm.
As time passed, Jaune became even more proficient in Magecraft, Aura manipulation and through Shirou's teachings swordmanship.
Everything seemed like it would keep going this way until one day a rift in space and time appeared before them and from it came a beautiful young woman with black hair in twintails dressed in a red top and black skirt. She was Rin Tohsaka, Shirou's girlfriend, and she finally managed to find a way to bring Shirou safely back home.
Sadly, she couldn't keep the portal opened much longer, it took a lot a mana for her to use the abilities of the Kaleidoscope, so they had to make haste.
The goodbyes were tearful and bittersweet. The two teacher and student grew really close to each other, close as brothers, and knowing that he might never see his teacher/big brother figure again made Jaune's heart break in sadness.
But fortunately Rin Tohsaka was here! The Magus genius promised that she'd find a way to connect Earth and Remnant more easily for allowing the two to stay in contact with each other. Despite knowing he could now take care of himself, Shirou was still very much worried about his student/little brother, especially considering what he learned of Remnant's forgotten past. So he was relieved to be able to come to his little brother's help if he'd one day would need it.
So after everything was said and done, and after Shirou packed up whatever he could carry back to Earth to study with Rin, he knew she'd be thrilled to have materials from another world to study, the two said their goodbye and crossed the portal. The rift shutting close as if it never was.
As he stood before where the portal was, for a moment Jaune believed that all these years were but a dream. These uncertainties were laid to rest when he flared his Aura and flooded his Magic Circuits, projecting a simple one-handed sword.
Jaune Arc was definitely going to realize his dreams.
And so, this day of beginning of a new term and his first year at Beacon Academy, Jaune Arc got off of the airship that brought him to the academy with a bright smile and full of hopes for the future. He couldn't wait to see what Beacon had to offer.
He sure wasn't expecting to be welcomed by the sound of an explosion.
A/N:
So yeah, I had this idea running in my head for a few days by now. That plot bunny was running rampant you have no idea...
By the way, it's not sure if I'll actually continue to write more of this. It's more of an experiment to test the waters, so to speak.
Your thoughts?
Fyr out.