The Crystal Onix

On Sunburst Island, Ash meets Mateo, a crystal sculptor who's searching for the Crystal Onix. Tracey's Marill uses it's super hearing to locate the Onix and, with Team Rocket on their heels, they arrive at a crystal cave. A Pokemon battle ensues with Mateo's Charmeleon weakening the Onix. When a spark of inspiration from the Crystal Onix hits Mateo's heart, his sculptures become some of the most beautiful ever.