I'm not sure if the act itself is described in any of the texts thought.
Nicci!
Seriously, girl looks fierce when she does that! I always preferred that actress to the other. Though, it's odd to think of her playing the softer side that she was playing at prior to the revelation that she was a Sister of the Dark.
I would have liked to see her in the Perdition fight scenes. I think that would've suited her well.