Pokémon the Movie: Diancie and the Cocoon of Destruction

In the underground Diamond Domain, home to many Carbink, the Mythical Pokémon Diancie rules as their princess. The land is sustained by a sacred jewel called the Holy Diamond, but it's slowly crumbling. Diancie isn't yet strong enough to create a new one, so it sets out to seek help from the Legendary Pokémon Xerneas. Along the way, it crosses paths with a band of thieves who aim to steal Diancie's diamond-creating power-and in doing so, they accidentally awaken the Legendary Pokémon Yveltal from its slumber. With disaster looming, Satoshi and his friends must aid Diancie in unlocking its full potential, calm Yveltal's destructive fury, and protect the Diamond Domain before it's too late.