Atem is the real identity of Yami. 3 000 ago he inherits his father (Aknumkanon) on the throne of Egypt and the reponsibility of protecting it from enemies and destruction. When The Dark Master Zork Necrophedius threatens Egypt, Atem sacrifices his soul to trap Zork in his Millenium Puzzle.
3 000 years later Atem's soul awakens again when Yugi Muto puts the pieces of the Millenium Puzzle together. Atem helps Yugi in his duels. Everyone call him "Yugi" until they find who he is and they help him to return in the past and find his memories. He is the Nameless Pharaoh for Yugi and his friends. To defeat the evil, the Pharaoh has to find out his real name. A-T-E-M-U (Atem, or Atemu in Japanese) is carved on a stone tablet hidden deep inside his tomb. Thanks to his knowledge of the future, Atem manages to summon the Three Egyptian Gods and becomes their master.
Translated from Bulgarian language by: Ted^Maverick (TV_Squad)