Pokemon Best Wishes! Season 2: Decolora Adventure - episode 6 - 29 May, 2013

Ash, Iris, and Cilan catch up with Professor Oak who has come to one of the Decolore Islands to investigate the Plasma Pokémon Rotom and its Forme Change capabilities. However, the Rotom native to the island are more interested in Pikachu, Emolga, and Stunfisk. (Source: Wikipedia)