The Megalith is advancing and the entire world is at stake. With everyone helping open the way, it's up to Ash and Alain to get into the Megalith to rescue Mairin's Chespin. Stopping the Megalith isn't easy and all the gym leaders come to aid. However, soon after the fight begins, Squishy and Z2 work together and begin to transform into Complete Forme Zygarde. Will the combination of Zygarde, the Gym Leaders, Sycamore, Diantha, Malva and Ash & Co. be able to save the world?