[she looks surprised for a moment, then sort of ashamed, looking down at her feet.]

Sort of... but not on purpose. I guess when Xigbar first... broke my Keyblade, I was really angry, and sad, but I kept training. And whenever I got frustrated, I'd get even angrier than normal, and then one day the wooden sword I was training with broke and I was so angry and the next thing I knew there was smoke and darkness coming off the training dummy...