complex insights into Voldemort's psyche, which he pieces together with Harry to deduce where Voldemort's horcruxes are hidden. Dumbledore's appearance hides a more steely aspect, as seen when apprehending Barty Crouch Jr who was masquerading as Mad-Eye Moody: "At that moment, Harry understood for the first time why people said Dumbledore was the only wizard Voldemort had ever feared. The look upon Dumbledore's face was more terrible than Harry could have ever imagined. There was no benign smile upon Dumbledore's face, no twinkle in the eyes. There was cold fury in every line of the ancient face; a sense of power radiated from Dumbledore as though he were giving off burning heat." However, in spite of Dumbledore's many extraordinary qualities, he is a flawed character. According to Rowling, "Although Dumbledore seems to be so benign for six books, he's quite a Machiavellian figure, really. He's been pulling a lot of strings." In a 2005 interview, Rowling commented: "Immense brainpower does not protect you from emotional mistakes, and I think Dumbledore really exemplifies that." Dumbledore's greatest flaw, which he admits to Harry, is his desire for power. He eventually finds that those best suited for power are those who do not seek it. When he and Grindelwald first meet, they make plans to enslave Muggles and re-establish wizards as the natural rulers of the world. However, Dumbledore becomes disillusioned of this fantasy after his sister Ariana is killed during a duel between himself, his brother Aberforth, and Grindelwald. Dumbledore is haunted by his sad family history. In particular, he is riddled with guilt over the circumstances surrounding the death of his sister. He feels enormous remorse for his selfishness in getting involved in the circumstances that led to her death, and is tortured for the rest of his life by the possibility that he might have been the one who cast the spell that killed her. When he looks into the Mirror of Erised, he sees himself redeemed in the eyes of his brother and his entire family alive and together. Magical abilities and skills Since a young age, Dumbledore has always shown great magical abilities. During his education at Hogwarts, Dumbledore was known as the most brilliant student to have ever stepped into the school, winning "every prize of note that the school offered", and in his N.E.W.T.s, "... did things with a wand [the examiner had] never seen before".