In a land called "Diamond Domain" there contains a powerful Heart Diamond that has served as the source of energy for the kingdom and has maintained the country for centuries. Carbink Pokemon live in Diamond Domain and serve there princess Diancie the jewel Pokemon. She created the Heart Diamond but doesn't have the power to keep the control over the Heart Diamon and because of it the land is falling into chaos. Diancie meets Ash and his friends and asks them to go and find Xerneas the life pokemon to heal the Heart Diamond. But Yveltal the pokemon of destruction is standing in their way preventing them from achiving their goals. Yveltal stole all of the life in Kalos Region once before. Ash and his friends are attacked by Team rocket, along with jewel thieves Marilyn Flame and Ninja Riot but get helped by Millis Steel and her father Argus which encountered the Cocoon of Destruction.