This one is really short, and a day late, but I really wanted to try a different angle, which led to this for some reason. Enjoy!
Cinder could never identify it. What about the girl that irked her to such a degree. She was just some kid. Some naive, inexperienced, clueless huntress wannabe. The rest of her teammates didn't bother her, at least not to this extent. They were annoying, but only as annoying as a couple of gnats buzzing around one's face were. Compared to them however, Ruby might as well be a swarm of cockroaches.
Then what kept bringing the girl to the forefront of her mind?
Sure, the girl had some clear talent, but not even enough experience to keep up with Emerald. She would be no big issue to their plans, if she even presented a problem at all. Cinder didn't expect to many problems though. If she could get past Ironwood's security with ease, getting past a few teenagers wouldn't be anything at all.
That didn't stop her from avoiding the girl at all costs. Only giving her sharp stares from a distance. Analyzing. Calculating just what it was that set off all her nerves whenever the girl entered her line of sight.
Maybe it was the eyes. The silver color alone was enough to set Cinder off, even if it was clear that the girl had no affinity for them. Salem's teachings ran deep though, and Cinder knew she couldn't disregard it completely just because the powers were still blocked.
Maybe it was her heritage. Rose was not a name spoken willingly in Salem's realm, not if one wanted to keep themselves alive. Roses were known for being unassuming. Overlooked for their soft and meek appearance. Only to lash out with thorns sharper and deadlier than ever expected.
Maybe it was the fighting style. Eerily similar to that bastard Qrow's. Not a good combination of traits.
Still, she had a plan to focus on. The kingdoms wouldn't bring down themselves after all.
She was just being paranoid. Letting something insignificant pester the back of her mind. The plan would be started soon enough. And then she'll see just how dumb her suspicions are.
Thank you all for your feedback! It gave me a whole new burst of inspiration!