The Journalist from Another Region!

As they reach the next island, Ash & Co. meet up with Alexa, a journalist from the Kalos region, and her Pokémon Gogoat and Helioptile which don't register on Ash's Pokédex. Alexa explains that she's in the Decolora Islands to research an article on the tradition of the island, the Harvest Festival. As they enter the festival, they learn of a special Pokémon Sumo tournament where the winner shall win the Focus Band, and some rare berries. Ash, Cilan and Iris each decide to enter this tournament, but things turn out to be tougher than they thought. Who will win the tournament?