Ruby never really knew what her cloak was made of. It was a gift, if she remembered correctly, from her mother.
She just never really thought about it, it just did what it did, even if she thought it was a bit odd.
Its size changed often, fitting her no matter her age or how much milk she drank, stretching over her form when she needed a full cloak and shrinking back to a cape the rest of the time.
She had vague memories of her early life, of when her mother was still alive, and she remembered how, just for a while, her cloak was a pure, snow white, just like her mother's. She remembered it not fitting in with her favorite clothes, a stark contrast to the reds and blacks she loved so much. It sucked, she remembered, how even then she felt an attachment to the garment, too bad it wasn't red...
And then, the next day, it was. Nobody, not even herself, even blinked an eye. She wore it every day, every night. She took it to school and to bed.
Her mother died soon after and she held onto it like a lifeline.
Ruby remembered loving the feeling of running in it, how her feet never seemed to tangle in the low-hanging cloak. She loved its fluttering, how she could go faster and faster and the fabric would raise higher and higher, until, all at once, a little girl who didn't even have her aura activated discovered her semblance as she shot across the yard of her house, sending her babysitter, a dusty old uncle, into a panic as roses were left in her wake.
There was a lot of yelling in her house after that, but all she had to do was pull her hood up over her ears to block it all out until Uncle Qrow grabbed her and Yang out the door with him. They stayed with him for a few days, and in this time had their auras unlocked and began their lessons on how to control it.
That was when Ruby learned she could make aura flow through her her cloak like it was a second skin. She could dissolve it into rose petals with her semblance like she could herself. Later, she learned to do the same with her clothes and, eventually, a weapon, but it was never quite as natural as her precious cloak.
The few days they were supposed to stay with their uncle became a few weeks, and after they learned what their uncle considered to be a sufficient level of defensive aura control, they began sparring.
Yang complained a lot, about the welts and bruises caused by the wooden staff Qrow used. He said she was doing it right, that she was supposed to get hit on the shins and forearms instead of her stomach, chest, or face, yet she complained nonetheless.
Ruby did better and worse. She could dodge most of the basic attacks even though she was supposed to be practicing blocks. When her uncle would speed up as a punishment, she'd always pull her cloak over herself in full, almost as an instinct. She'd eventually take hits as Qrow went faster and faster, but having the cloth in between her and the staff minimized both damage and pain. She always somehow ended up getting hit more than Yang but their sting never lasted for more than a minute and, as she grew more and more adept and controlling her Aura, she felt them less and less.
Soon they moved on from blocking strikes while unarmed to blocking strikes with a staff not unlike Qrow's, though shorted to be better proportioned to their height. It made more sense to Ruby now to prioritize blocking, since she wouldn't have had her Aura chipped away at anymore. She learned as fast as she moved, figuring out counter attacks before she was taught them and keeping up with a surprised Qrow, even if he was toning down on his own abilities in order to teach them.
Looking back on it, these training sessions were some of the few times Ruby saw Qrow sober.
Eventually, Yang got fed up with the staff and, in the middle of a session with Qrow, threw it to the ground and charged him, burying her fist in his gut. Though she somehow only ended up hurting herself in the process, Qrow agreed to teach her what he knew of hand to hand.
Ruby, however, embraced the staff as she got better and better. Her cloak hanging down her back only ever seemed ti get in the way of Qrow, tangling with his staff more than once to allow Ruby a free shot. He never said anything about it though, Yang only giving some complaints in their brief spars.
Soon enough either Qrow considered them ready enough or Taiyang got his act together because Ruby and Yang were back living with their dad, receiving his training along with their uncle's. Yang was enrolled in Signal as soon as she was old enough and Ruby followed two years later.
These years sped by in a flash of accomplishment as Ruby rose to the top of every class. She won every fight that wasn't against an instructor, her dad and Qrow drilled every word in the textbooks into her, and she built the best weapon ever conceived. Eventually, she skipped two whole grades, giving her father, uncle, and even Yang watery eyes when Ozpin invited her into Beacon.
Her cloak did even more here: withstanding all matter of elemental attacks from Weiss, resisting any projectiles shot at her by Ren, and downright ignoring tooth and claw from more Grimm than she could count.
Then Beacon fell, Pyrrha died, her team left her, and when she was forced to face the realities of a true hunter, her cloak was truly put to the test.
She encountered rare species of Grimm, ones they hadn't been told about in Theory or Grimm Studies; big cats with claws the size of her torso, balls of slime that made the ground they tread across turn to pools of melted acidic material, even a living tornado that threw team RNJR around like ragdolls.
Ruby was bruised and bloodied, forced to change her entire outfit multiple times within the first few months.
But never her cloak.
It took the fire breathed from alligator Grimm and shrugged it off like it had an aura of its own. It survived the acidic jaws of zombified villagers with nary a scratch. It took a friendly, electrified grenade from Nora - a result of miscommunication as Ruby learned to lead a new team - and didn't even allow the dust to settle on it.
It was, Ruby was sure now, magic.
Qrow had told them about the Wizard and his Maidens, about her Silver Eyes, about the relics hidden in each of the schools. Ruby trusted Qrow and, even if she didn't. she'd witnessed firsthand Cinder's power at the fall of Beacon.
She also suspected her mom had something to do with it all. If she did, would it be too far a leap to think her cloak was magic? Ruby didn't think so.
It was old now, almost as old as she was. It had tears and rips from adversaries so strong, even her cloak couldn't entirely resist them. But it held strong, even after all this time.
Ruby didn't like taking off her cloak, even to bathe. It felt as am extension of herself, even more so than her weapon. Her teammates had mentioned the relief of seeing the red cloak during a losing battle, to know she had their backs, to know someone they trusted and loved was watching. It was more than just what it did, it was what it symbolized.
It made her feel invincible, like she could adapt to any environment, face any challenge, and help any of her friends. It made her feel like the hero everyone described her mother as.
It made her think about how she kept going when she shouldn't have been able to. How she refused to be forced from her friends like Weiss, how she refused to run away like Blake, how she refused to give up like Yang.
How she refused to die like Pyrrha, like Penny, like her mom, like the countless other hunters and soldiers throughout history who died because they weren't enough for the task, for misunderstandings and mistakes, who died for unknown reasons because they couldn't make it home to tell the tale.
Ruby didn't want to be a hunter anymore. They all died protecting what they loved.
No, she wanted to be like her cloak. She wanted to save everyone and get through it with nothing for than a few tears and burns so she could do it again and again. Her cloak was magic, she was sure of it, but so was she. She had the silver eyes her uncle had told her about.
And there was no way in hell she'd die like her mom.