Board Thread:Speculation House/@comment-131.123.61.0-20140416144504/@comment-3146930-20140418190234

In reply to 99.185.49.181:

As far as Pyrrha controlling Jaune's shield by concentrating, I don't think she was trying to slowly move it so that Jaune wouldn't notice. The more likely explanation is that Jaune was far away, forcing her to focus more. There were a few times in the first half of Volume 1 where Pyrrha could call her spear back to her, but she was very close to it. With Jaune, she was far enough away where Cardin or Jaune didn't even notice her, Weiss, and Ruby; so the fact that she needed to focus was probably distance related.

As far as Weiss being tired after the Nevermore attack, she doesn't seem too tired before the scene shifts to the naming ceremony. However at about the 10:28 mark, right after she makes a trail of Glyphs up the cliff, she clearly appears tired so a Semblance can deplete a person's energy. The same may be true for Ren, as he seemed fine after the fight with the King Taijitu, but in the next episode he is clearly tired when him and Nora arrive. He also completely passed out after his team defeats the Death Stalker and is never seen using his Aura as he did earlier, so Aura may also drain a person's energy (but there obviously could be other factors). It is hard to tell with other characters, as only Weiss really used her Semblance to such a large degree, making multiple Glyphs back to back.