So this little idea came to me after rewatchign the finale of Rebels, not goign to spoil to much before this prologue.

Millennia ago, the creatures of Grimm, horrible beasts drawn to negative emotions with nothing but murder and destruction on their minds, had nearly wiped out the Faunus, the native species of Remnant. But in their most desperate hour, our ship, the Omen, crashed on the planet's surface and, with the force on our side, we ensured their survival.
After this, we began to help their civilization flourish, serving as mentors, protectors and even leaders to the natives. But even as we shared the ways of the force with them, the need to adapt our ways due to the Grimm became evident. With hatred and anger drawing their attention, leaving our temples besieged for days on end, we began to draw our strength from less aggressive emotions.
But even so we Sith grew stronger each generation, interbreeding with force-sensitive Faunus to heighten our children's senses and reflexes. Thus we will be ready to take our rightful place as rulers of this galaxy at our brothers and sisters side once we find a way-

"Ruby you reading Mom's old stories again?" Yang asked her half-sister, arms crossed before her leather clad chest as her long mane of blond hair swayed from side to side with the shake of her head, barely ending above the scaled tail swaying from side to side behind her as she approached her sister.

A pair of wolf ears twitched amidst the addressed girl's dark red hair as she looked up from her scroll, a more advanced version of the datapads her ancestors brought with them as they crashed on Remnant. "Yes" Ruby answered as she looked her sister in the eyes. "Reading them I feel like Mom is still here, at least in spirit."

"Oh, Ruby never change." The Blonde comments quietly as she hugs her younger sister. "Come, let's go outside for a little spar"

With only a simple nod in reply the two girls grabbed their respective weapons as they headed into their families backyard, where a simple square of bare dirt was set aside for practice.

When the two young Sith had taken their position at opposing edges of the patch of dirt, they readied their weapons.
Yang took a slightly relaxed stance, arms raised in a simple boxing guard, before igniting the crimson blades attached to her Gauntlets, which would allow her to stab through an enemy. That is if she had not reduced her weapons energy output, so they would only cause minor burns even if the opponent was unable to channel the Force into a protective Aura.
Ruby meanwhile was holding her red and black saber pike with both hands, a blade colored such a deep red that it appeared black except for it's edges at one end. The blade's hum was higher than her Sister's weapons. Both these were caused by the crystal focusing her blades weapon, which had been handed down through her family since they arrived on Remnant aboard the Omen.

As they began to exchange blows, a loud bang stopped them in the middle of the blonde's punch, before a low whistle filled the redhead's canine ears. Looking for where the sound came from, the two could barely make out a small, seemingly triangular shape trailing strangely round debris as it descended toward the continent of Anima.

"What is that?" Yang asked as she followed the object's trajectory.

"I have no idea. But it looks like it will crash into Grimm territory." Ruby offered, an easy guess to make seeing as the Island of patch the girls lived on and the city of Vale were the only densely populated areas on the northern parts of the continent.

"We could ask Uncle Qrow once we can reach him." Ruby suggested, sure that her former teacher would know more than they do.

"Isn't that Master Qrow?" Yang asked jokingly.

"Nope, not since he made me a Saber." Ruby countered, bringing up her recent raise in rank after completing the training of an Apprentice at the age of 15.

Trying to blindside her sister, Yang sent a fist towards her sister's stomach. But instead of impacting her flesh or Aura, the punch was stopped by the Dust enhanced shaft of the wolf eared girl's weapon. Simply smiling at her sister, the redhead then sent the lower end of her reignited weapon at her sister's side, just to be stopped by a gauntlet clad hand before it could connect.
As Yang began to punch Ruby quicker and quicker, enhancing her muscles with the Force, the younger girl realized she needed to get some more space between them to use her weapon of choice effectively. With a wave of her left hand, she send the lizard tailed Faunus sliding back, despite Yang's attempt at resisting her sister's use of the Force.
With the blonde now at a better range for her, Ruby began to utilise the reach offered by her weapon with ease, keeping Yang at bay as the blonde's shoto blades couldn't reach her sister. It took a few moments, but finally Yang managed to grab onto her Sister's weapon, which allowed her to once again close in on Ruby.
Their spar continued like this for a few minutes, the two year younger Ruby making up for her lack of strength and experience with a stronger connection to the Force, until the two of them received the same message on their scrolls, causing them to stop the spar as they read it.

Saber,

report to High Lord Ozpin at Beacon temple at noon tomorrow.
Do not be late.

Lady Goodwitch

"Any idea what this is about?" Ruby asked her sister as both of them shut down their weapons.
"Not the faintest, but we should make preparations to travel to Vale tomorrow." Yang said as she led the way back into their family's surprisingly humble home.
Folding the staff like shaft of her weapon in half before attaching it to her belt at the small of her back, Ruby followed after her Sister.

"Couldn't we just take your speeder to the coast and take a ferry from there?" The wolf Faunus ask as she catched up to the blonde.

"Yes, but I need to check which is the last one we can take without being late. You know I despise getting up early." Yang replied, smacking her little sisters behind with her tail.

So in case you missed it, or are not as familiar with the old Starwars Expanded Universe, this Story is based on the premise that instead of Kesh, the Lost tribe of the Sith crashed on Remnant instead.

I hope you all enjoyed this prologue, if not I would like to hear why.

For those fo you who are hoping/waiting for updates on my older stories, I wrote this down as I tried to get back into the swing of things for Aliit and Grimm Rose, both of which I do hope to have new chapters again for in the next few months.