The Dark One Cometh: Part 1 - S5-E31
Continuity mistake: Yugi activates the spell card Marshmallon Glasses, which he equips to one of Bakura's monsters. Seconds later, when Yugi says "and my life points are safe too," his two monsters can be seen on the field, but the spell card cannot be seen. At the end of the scene, there is a wide shot where the spell card is visible in front of Yugi and visible behind the monster on the left-hand side of the field, which means it should have been seen in the earlier shot when he said his life points were safe. (00:11:38 - 00:12:28)