Board Thread:Speculation House/@comment-24718692-20140322030224/@comment-28277272-20140322082312

This may be only speculation, but I think it was implied semblance is linked to aura. As far as we know, aura can be activated (which means it can be desactived too), characters may also run out of it without being hurt (Jaune is fine even though he doesn't activate his aura). It seems to work as MP/mana in videogames, even if the character runs out of it, it is different from HP/health.

On that idea, I guess Ruby is the fastest when she uses her semblance. But hypothetically, if all of the characters were to be out of aura (or unable to use their semblances), Weiss would be faster. Comparing to videogames once again, Ruby's semblance would be like a magic skill that allows her to be incredibly fast, but uses up some MP/mana.

If you look at chapter 4 (episode 6, I think?), when Weiss and Ruby runs away from the beowolves, Weiss seems to be ahead of Ruby. Also, Weiss is incredibly fast when she runs to the Death Stalker in order to save Ruby, or when she gets back from the Nevermore after frozing it, in episode 8. Thing is, Weiss doesn't exactly 'run', her legs don't move, and we don't know if that's a choice from the producers (as it would be too hard/long to do the animation?) or if she actually uses her aura to do it.

As I said, only speculations. But she does seem faster than Ruby in some cases.