According to Mrs. Whatsit, why is Charles Wallace in more danger on Camazotz than Meg or Calvin?

In
chapter 6, the Happy Medium uses her crystal ball to show the children the battle between the
Dark Thing and the stars. Mrs. Whatsit says that she was once a star and sacrificed her
celestial existence fighting the Dark Thing. Before the children embark on their journey to
planet Camazotz, Mrs. Whatsit, Mrs. Which, and Mrs. Who present the children with different
gifts that will help them accomplish their task and survive the hostile planet. When Mrs Whatsit
instructs Calvin to take care of Meg, Charles Wallace responds by saying that he can take care
of her on his own. Mrs. Whatsit then explains to Charles that he is in the greatest danger on
planet Camazotz.

Mrs. Whatsit proceeds to tell Charles that he is in danger
because he is a proud child prodigy who is too confident in his intelligence and abilities.
Since Charles is a genius, his pride will be his downfall. Mrs. Whatsit also warns Charles by
telling him that he must not go off on his own and that his pride and arrogance will jeopardize
his well-being. Mrs. Whatsit's warning foreshadows Charles's fate. After arriving on Camazotz,
Charles dismisses Mrs. Whatsit's advice by staring at the man with the red eyes in an attempt to
know more about his father. Charles is too confident in his own intelligence and abilities to
realize that he is putting himself in extreme danger. Tragically, Charles becomes brainwashed by
IT and must rely on his sister and Calvin to rescue him.