Cynthia is the Pokémon League Champion in Pokémon Diamond and Pearl.
She is the Champion of the Sinnoh region and serves as the final opponent after the player defeats the Elite Four. Cynthia also appears throughout the story as a Pokémon researcher interested in Sinnoh's myths and history.
Her signature Pokémon is Garchomp, a powerful Dragon- and Ground-type species. Cynthia's balanced team and high-level Garchomp made her battle notably difficult for many players, helping establish her as one of the most memorable Champions in the series.
Cynthia returned in Pokémon Platinum and the remakes Pokémon Brilliant Diamond and Shining Pearl. She also appears in other games and in the anime, where she is portrayed as an experienced Champion. Leon is the Champion of Galar, Steven Stone is associated with Hoenn, and Iris is the Champion of Unova in Pokémon Black 2 and White 2.