Gilbert is the leader of the Gym in Flint City, and a master of Dark Type Pokemon. Gilbert himself is a tall, slender man, with short black hair and square-rimmed glasses. He wears the outfit of a simple office worker, with a pair of black pants, a white collared shirt tucked into his pants, and a black tie. He's very calm and collected, with a cold aura of ruthlessness about him. He speaks in a soft voice that carries a hint of danger in it. His Pokeballs are carried discreetly on his belt. His Umbreon does not go in a Pokeball, but rather stays at his side.

Gilbert's Gym is much like himself; rather nondescript, but in some way deeply frightening. The arena is made up of dark metal and concrete, with low, cool lighting that simulates the ominous darkness of early night-time. The two trainers stand on opposite sides of the arena, which is twenty meters long and ten meters wide. It is on a raised platform, about a meter off the rest of the ground, with a traditional Pokemon battlefield etched into the dark concrete. There are no windows in the large arena, and the spectator stands are simple benches set back from the field by about five meters. The hard floor makes it exceptionally hard to break or dig through.

When defeated, Gilbert gives up the Pitch Badge, a small black rhombus signifying the trainer's triumph over the powers of darkness.