Yu-Gi-Oh! Duelist Duel 155: "The Cursed Bloodline!"
Little is known for Mr. Ishtar's early life, but as the first born son of the Ishtar clan, he had the Pharaoh's stone tablet symbol carved onto his back at age twelve. Sometime later, he got married.
When Rishid was adopted, Mrs. Ishtar, who loved Rishid as a real son, considered to allow him to become the heir of the clan if they did not have a son by Rishid's tenth birthday. Her husband, who did not share the same love for the boy, reluctantly agreed. When Ishizu was born, the couple was disappointed for not having a boy. However, four years later, Marik was born, and though Mrs. Ishtar died giving birth, the clan finally had its heir.
Rishid was then assigned as a carer for Marik, on his father's instructions. When Marik got bitten by a cobra, Mr. Ishtar was furious with Rishid's lack of carefulness, and ordered him not to leave Marik's bedside until he was fully cured, threatening him with death for any future failures.
When Marik was reaching his age of taking the clan's tradition of bearing the carvings on one's back through a ritual, Marik tried to refuse, and Rishid offered to take his place, but Mr. Ishtar refused, angrily stating that he was "just a servant", and threatened to cut off his tongue if he asked again. It was this point that he revealed that he never once considered Rishid as a full-fledged member of the clan, and even refused to accept him as a son.
Mr. Ishtar then proceeded to use the Millennium Rod's concealed knife to carve the Pharaoh's stone tablet symbol onto his son's back, ignoring his protests and cries of pain, which also spawned an alternate personality.
When Rishid cut his own face with his own carvings to ease Marik's anger, Mr. Ishtar finds them repulsive, and kept ordering Rishid to wear something over his face, and continued to refuse him as a member of the family.
About a year later, Marik convinced Ishizu to go see the outside world, while Rishid kept watch from letting their father find out. Unfortunately, when the siblings departed, they unknowingly triggered a silent alarm, which alerted their father. Mr. Ishtar was beyond furious, and punished Rishid by slicing him with heated blades.
When Marik returned, he tried to stop his father from hurting Odion, but the man merely pushed him aside and proceeded to torture Rishid to a presumed death. He then proceeded to order his son to accept his punishment. However, as Odion was unconscious, nothing was to stop Dark Marik from awakening. Dark Marik then sarcastically thanked his father for "killing" Rishid. His father, who was unaware of this split personality, was unamused and attempted to punish Marik.
However, when Dark Marik took the Millennium Rod, his father's indifference turned into fury, ordering him to put it down and accept his punishment. When Marik refused, he tried to lunge at his son. Dark Marik then used the Millennium Rod to slam his father against a pillar, as well as a protesting Ishizu. With his mobility disabled by the Rod's power, Mr. Ishtar's last words were an angry order for his son, who was advancing with the Rod's knife, to stop. Dark Marik, being born of pure hate, sneeringly ignored this final order and proceeded to cut out the tattoo on his back and threw the skin onto the unconscious Rishid. Before his death, Mr. Ishtar's anger turned to pure horror as he realized his own son was going to kill him, and his scream was loud enough to travel throughout the entire underground. When Marik woke up, he believes it was the doing of the Pharoah, as Shadi rose behind his father's body and told him the Pharaoh would be coming soon.