Castle Valet Darach and Lady Caitlin

Darach (Japanese: キャッスルバトラー コクラン Castle Butler Kokuran) is the fourth Frontier Brain in Sinnoh and Johto region. He is in charge of the Battle Castle

Trivia

 * Though the player battles Darach, Caitlin is the true Battle Castle Frontier Brain.
 * Darach and Caitlin appear together, but they do not participate in double battles.
 * Caitlin is also a member of the Unova Elite Four in Pokémon Black and White (Gen 5) and Lady Caitlin is her younger self.
 * He appears in the Pokémon Adventures Platinum Arc as a Frontier Brain.