Lyndon, known as Leo in the Japanese version, is Zora's son, who lived away from her for three years after an argument.
As a child, he had always enjoyed watching his father repair clocks until his father died. When Lyndon was older, he tried tightening the screws of Zora's cuckoo clock and accidentally broke it. He and Zora had an argument and Lyndon decided to run away. Lyndon spent three years training on how to fix clocks, so he could try to fix his mother's clock again.
He finally returned to the garage of Yusei Fudo and his team, which used to be his home, and explained to them what had happened. They helped him dress up so he could apologize to his mother and try to fix the clock again. However, when he tried to, Zora wouldn't let him, thinking he wasn't good enough. When Lyndon turned to leave, Crow Hogan challenged him to a Duel. If Lyndon won, he could do as he chose, but if Crow won, Lyndon would apologize to Zora. As the Duel progressed, Lyndon wanted to give up, but Crow called him a child who wasn't willing to try. At this retort, Lyndon continued. He drew "Time Wizard", a card his father gave to him when he was young. Lyndon was able to win the Duel using this card, though Crow didn't activate his face-down "Mirror Force". Lyndon remembered the joy he felt watching his father repair clocks, and that his father told him that the things Zora did were because she cared about him. Remembering why he had trained so hard, Lyndon fixed the clock, having won his mother's love again.
During Yusei's Duel with Z-one, he and Zora are seen cheering on Yusei.