Ishizu Ishtar

Marik's elder sister. Ishizu became a museum curator in order to lure Yugi Muto and Seto Kaiba to her in order to keep Marik from fulfilling his goals. To aid her, she holds the Millennium Necklace / Millennium Tauk that has the power to foresee events in the near future. Despite her brother's betrayal of their family, she still loves him very much and believes that there is still good in his heart. She continued to seek a way to return him to the person he used to be, even as he became more cruel. She is committed to her family's destiny to serve the pharaoh, as she believes that he is the only one with the power to stop Marik. In an attempt to save him, she enters the semi-finals of the Battle City, diguising herself as the mysterious eighth duelist. (Source: Wikipedia, Yugipedia)