Pokémon season 15

what happens

As Ash and his friends continue to explore the Unova region, he’ll find himself up against the ultimate battle challenge: Alder, the Champion Master of Unova! His friends also face their own trials, one fighting for the right to continue her travels, another confronting a returning challenge from the past—and all three of them must team up to save an island from the clashing forces of three powerful and mysterious Legendary Pokémon!