Watch S02yu-gi-oh 78 -

Note that "Episode 78" refers to different plots in other Yu-Gi-Oh! spin-offs:

The group reunites on the dock. Kaiba, having helped save Tea by disabling a crane trap with a Blue-Eyes White Dragon card, departs to prepare for the Battle City finals. Series Comparison Watch S02Yu-Gi-Oh 78

This episode concludes the high-stakes "Anchor Duel" between Yugi and a mind-controlled Joey Wheeler, orchestrated by Marik Ishtar. Note that "Episode 78" refers to different plots