Atem, also known as Yami Yugi, is a central character in the Yu-Gi-Oh! anime series. He is the spirit of an ancient Egyptian pharaoh who resides within the Millennium Puzzle, sharing his body with Yugi Mutou. Atem is wise, confident, and fiercely protective of his friends, often taking control during difficult Duel Monsters battles. His mysterious past and journey to recover his memories are key elements driving the story and the development of the main characters.