Just an idea that I had last night that wouldn't leave me alone. Set at the end of volume 5 with a slight canon divergence. Enjoy!
Sometime after she sends her sister into the Vault after Cinder and Raven, Ruby becomes vaguely aware that she feels—different, somehow. She can't quite put her finger on why or how, but there's a strange feeling prickling under her skin, almost like some sort of electric current. There's a heady rush of strength and power, almost like the first time she was able to access her aura, when Yang unlocked it for her, but where is it coming from? It's almost as if someone is boosting her aura, but Jaune is nowhere near her right now.
Whatever it is, she doesn't have time to focus on it right now. Despite the current odds clearly not being in their favor, Emerald and Mercury are putting up a strong fight. And as if it weren't enough that both of them on their own are strong opponents, together they make a formidable team. Even with Weiss and Blake backing her up, it's going to take all of her concentration just to hold them off.
Emerald is insistent that Cinder will return triumphantly any moment now, with the Lamp of Knowledge in hand, ready to strike them down. Ruby remembers Emerald's earlier insistence that if Ruby wanted to fight Cinder, she'd have to fight her first. The green-haired girl seems quite attached to Cinder, refusing to even think about the possibility that the Fall Maiden would fail.
Privately, Ruby has her own doubts that she's trying to quash down. She trusts Yang, of course she does, and she's well aware that her sister can hold her own in a fight. But—so could Pyrrha. Pyrrha had been among the strongest fighters in their class, and Cinder had still struck her down in the end. And Yang is strong, yes, and she's improved since they were at Beacon, but she's still facing down three very strong opponents, including the Spring and Fall Maidens. And Yang is alone.
But dwelling on her sister's odds of success won't help anyone, so Ruby shoves her worries and doubts to the back of her mind, determined to focus on the fight in front of her. The best way she can help her sister right now is not to fret about things she can't change, but instead to not make Yang have to fight more when she returns.
And then Yang is there, holding the Lamp of Knowledge triumphantly. There are dried tear tracks on her face and her eyes are ringed with red, but she looks relatively unharmed. Ruby allows herself a fraction of a second to breathe a sigh of relief at her sister's successful return—only to be interrupted by Emerald's scream.
She can't tell if Emerald is screaming in rage or pain or desperation, or a mixture of all three, but the other girl clearly isn't taking the news well. Emerald continues to shriek, and suddenly Ruby's vision is filled with a strange woman, her skin ghostly white and pale hair contrasting sharply with her dark eyes. Her red irises seem to bore into Ruby's very soul.
Ruby has no idea who this woman is, but she seems incredibly dangerous.
Startled, she stumbles back a step, raising her arms in front of her face. As if triggered by her panic, she feels power surge within her—and suddenly, a thin stream of flames hits the woman squarely in the face.
Where did that come from?
Ruby blinks, and suddenly the woman is gone. She must have been one of Emerald's illusions. With a sigh of relief, she drops her arms.
Emerald, Mercury, and Hazel are gone. They must have fled while they were distracted. She looks around to see everyone staring at her. "What's going on?"
Weiss looks at her like she can't quite believe what she's seeing. "What was that, Ruby?"
"What was what?" It's only then that Ruby realizes that the tiny flickers of light she keeps seeing in the corner of her eye are actually from the silver flames blazing around her eyes. "Oh."
Thank you for reading! Please leave a review if you liked it.
Just a reminder that I do take requests for fics, so if there's an idea that you'd like to see me write, feel free to message me and if I like it, I might end up writing something for it. Also, if you like one of my ideas and want to write your own fic for it, feel free! I'm not possessive with my ideas, and most of my writing is self-indulgent anyway, so all that I ask is that you let me know so I can read it.