Board Thread:General Discussion/@comment-203.129.23.222-20130906131117/@comment-3257939-20140911004320

It may be due to the fact that Pyrrha hides the fact that her semblance allows her to control her enemies once she touches them to give the illusion that she's invencible but in reality, she's just controling the battle. It can be seen as someone who is arrogant in a sense for making a title for herself for something that is not. I know it's not really cheating or anything but just like Cinder said: People assume that she's fated for victory, when she's really taking fate into her own hands.

Therefore, Pyrrha is hiding it for the sake of her title as the "invincible girl" which is arrogant in a way and it's related to her power.