Pokemon XY&Z - episode 42 - 14 Sep, 2016

Ash and Alain continue their battle against Lysandre, succeeding in defeating Mega Gyarados. Meanwhile, Chespie is absorbed by the Megalith Crystal in Lysandre Labs, which transforms into a giant Megalith Zygarde. The Megalith Zygarde then proceeds to head toward Anistar City to absorb the power from the Anistar Sundial, which will result in a planetary apocalypse. Ash, Clemont, Serena, Alain, Sycamore, Malva, Steven Stone, the Kalos Gym Leaders, and the Kalos League Champion Diantha join forces to defeat the Megalith Zygarde. (Source: Wikipedia)