Odion took part in the Battle City tournament, where he posed as Marik Ishtar, while the real Marik took part, using the disguise "Namu". Odion arrived at the stadium site, as the last finalist, moments before the deadline. He then boarded the airship with the other finalists.
Odion was matched up with the player for the second of the quarterfinal Duels. Yugi began to suspect that he was not Marik at this point, due to Millennium Item holders being able to sense others like them on an instinctive level and not feeling the same sense of evil that he felt from Marik before. Before the Duel began, Odion said that the player would be judged by the will of the gods and fall before his God card. Upon his defeat, he said that the gods had forsaken him. Since he used "The Winged Dragon of Ra" despite not being its rightful owner, the arena was struck by unusual weather. The real Marik Ishtar then identified himself and Odion begged him for forgiveness. Odion then fell unconscious, allowing Yami Marik to take control of Marik's body.
The following cards can be won from Odion by the ante rule, provided the player does not wager a low-level ante card. The chance of winning a card is indicated by the "%" (chance out of 100) and "2048th" (chance out of 2048) columns.
