Hapu is the new kahuna of Poni Island! After her confirmation ceremony, she agrees to battle Ash in a grand trial. It’s a one-on-one match between Mudsdale and Pikachu, with Kiawe as referee! As a Ground-type Pokémon, Mudsdale is immune to Pikachu... (more)’s Electric-type attacks. On top of that, its Ability raises its defense every time it gets hit! Things are looking dire for our hero when Pikachu maneuvers Mudsdale to the edge of the battlefield—where it gets completely soaked by a wave. And since water conducts electricity, Ash and Pikachu win their fourth grand trial with a devastating Z-Move, and Ash gets a new Z-Crystal: Steelium Z!