Zero was a psychotic and egotistical woman who believed all she did, regardless of how horrific, was for God's sake. In her view, every event and encounter was a deliberate act by God to push her towards her 'destiny' while everyone else were nothing more than stepping stones for her ascension. She also believed she was the only one chosen by god, therefore she hated the idea when Isabella implies that her god is protecting a mortal like Roland.