The atmosphere turned quiet after Ziel said that and stood in front of Princess Cordelia. Kyouka and Megumi could only gulp and see what Ziel would do. After seeing Ziel's cold gaze directed at her, Princess Cordelia subconsciously stepped back. Princess Cordelia realized that what she said earlier was too much, and she shouldn't have said that to Ziel. Ziel can do anything to her when she's at her best, especially in her current state.
Even so, Princess Cordelia wouldn't go back on her words. She wants to provoke Ziel to help King Raghnall and the soldiers of the Cirlus Kingdom. But Princess Cordelia underestimated him too much. Ziel didn't act according to what she wanted.