What happened in the last episode:

The Battle City finals had begun. In the first fight, Yugi and Bakura faced each other. It looked bad for Yugi, but he won with Slayver, the sky dragon. In the second fight, Joey Marik's lackey encountered Odion. Marik smuggled a fake winged dragon card into his deck that made him lose. Since he was Marik's protector, his evil side broke out. In the third duel, Mai lost to Marik. May was banished to the realm of shadows. In the last duel of the quarterfinals, Ishizou won against Kaiba, who, however, kept Obelisk.