Yami Marik turned his Duel with Yami Yugi in the finals into a Shadow Game that gave him a clear edge; when Yami Yugi lost Life Points, Yugi Muto's body would fade away, and when Yami Marik lost Life Points, the original Marik would fade away. While Yami Marik would survive if Marik didn't, if Yami Yugi lost, both he and Yugi would be destroyed. Discarding "Ra" on his first turn, Yami Marik helped Yugi get "Slifer the Sky Dragon" out so he could destroy it himself with "Ra", which he succeeded in doing with Egyptian God Phoenix. He reclaimed his "Monster Reborn," giving Yami Yugi a last chance to draw. Yami Yugi didn't even look at the card before he Set it, but Yami Marik wasn't interested. He brought out "Ra" again, this time using its Point-to-Point Transfer effect to raise its ATK and prepared to attack. He also revealed that he had taken the Millennium Ring from Yami Bakura, revealing that he was behind Bakura's disappearance to the group at large. When Yami Marik attacked, Yami Yugi revealed the card Kaiba had given him - "Fiend's Sanctuary," which forced Yami Marik to attack himself. Yami Marik was forced to use the "De-Fusion" that Yami Yugi had given him through "Exchange," separating himself from "Ra" and boosting his Life Points.
Yugi then Summoned "Obelisk the Tormentor" and attacked Yami Marik directly, badly injuring him, but this gave Yami Marik the opportunity to create a clone of it called "Egyptian God Slime." He used the Slime to stall until he could revive "Ra" to destroy "Obelisk," but Yami Yugi prevented this by using "Slifer" as a shield. Yami Marik simply revived "Ra," and began to boost its ATK, only for Yami Yugi to sacrifice the "Egyptian God Slime" to activate the effect of "Obelisk," boosting it to infinite ATK. Yami Marik blocked the attack with "Class System," and prepared to finish Yami Yugi off, attacking "Obelisk." Yami Yugi responded with "Ragnarok," that would destroy "Ra." While Yami Yugi and Yami Marik Dueled, Odion woke up and made Marik realize that he had to accept his responsibility for being a Tomb Keeper and the death of his father. With this confidence, Marik overpowered his evil self and urged Yami Yugi to attack him. Yami Yugi did so, destroying "Ra." The shock of the monster's destruction while Yami Marik was fused to it allowed Marik to retake control, putting Yami Marik in the position of the sacrifice. Yami Marik begged his other self to work with him, but his efforts were in vain. Marik forfeited, reducing his Life Points to zero and resulting in the ultimate destruction of Yami Marik.