S1·E6 The Ultimate Team No More?

Although Agumon and Marcus work well together to defeat a Tortomon, Agumon gets angry at Marcus after a comment of his and now hides in his Digivice. Meanwhile, an Elecmon wreaks havoc in the city, causing car crashes. Marcus tries to defeat him alone, but Elecmon Digivolves to a black Garurumon, which even Sunflowmon and Gaogamon can't defeat. Marcus and Agumon must work together again to beat this new threat.