Allister

Allister is a Gym Leader and an user of -type Pokémon.

Personality
In spite of being entitled as a Gym Leader at his young age, Allister is exceedingly introverted and bashful, hence always wearing a mask to conceal his face when he's around other people. He prefers spending his time alone in ruins and cemeteries rather than making public appearances.

Trivia
So far, Allister is the youngest Gym Leader in the franchise.