Along the way, Diancie uses her powers as a Jewel Pokémon to create Carbink companions to help protect her and Ash's team. However, they soon discover that the Carbink are being captured by Marilyn Flame and Ninja Riot who are after the Life Pokémon's power. With the help of Millis and Argus, they are able to rescue the captured Carbink and continue on their journey.
As they get closer to Xerneas, Yveltal begins to awake and threatens to bring destruction to the region once again. Ash and his friends must face off against Yveltal to protect the Land of Kalos and restore order to Diamond Domain. With Diancie's power and the help of the Life Pokémon, they are able to defeat Yveltal and restore the Heart Diamond's power.
Throughout the journey, Diancie learns the importance of friendship and trust as she forms a close bond with Ash and his friends. The movie ends with Diancie returning to Diamond Domain as a stronger princess, ready to lead her people into a new era of prosperity and peace.
