Seeing Shin coming toward her with his army of star souls, even Ann felt a little threatened. So immediately she decided to not play around anymore.
After their transformation into Fiendish Humans, both of the ladies had gotten some special abilities outside of their spell casting capacities from before.
As for what ability Ann had gotten, it was the power to inflict "Rot". Rot was a very powerful ability that could forcefully age everything around her. As this was a new power, her control over it was not very good.
But she did not care about that at all. Having less control did not make her abilities any weaker. So as she did not care about the side effects of having an uncontrollable power, she did not mind her lack of control.
And seeing Shin coming toward her, this was the exact power that she activated. The area around her immediately turned into a zone of death.
