Calreath is the Gym Leader of Amphitrite City's Gym, known officially as the Amphitrite Gym. As he has yet to appear in the story, it is unknown what type of Pokémon he uses as well as what rewards he bestows to players that defeat him in battle.
In the game
Calreath has yet to make an appearance in the story but it is confirmed that he is the Gym Leader of the Amphitrite Gym as well as the current boyfriend of Diana, the Gym Leader of the Selene Gym.
Pokémon
As the player has yet to battle Calreath, it is unknown what Pokémon he uses in battle. However, it is confirmed by a resident of Selene City that he, like Diana, has managed to befriend a legendary Pokémon. Diana also confirms Calreath utilizes a Rain centered team.
Sprites
Trivia