Alice, Guardian of the Departed

Alice is a gym leader in the Illidar Region who specializes in Ghost types. Her gym takes place in a mausoleum where those who died from the wrath of the Cruciferi. Upon defeating her, her opponents receive the Grave Badge and TM 61 (Will-o-Wisp).

1st encounter
Yamask, Litwick

Rematch
Dusknoir, Banette, Froslass, Confagrigus, Gengar, Chandelure

Trivia

 * The TM given isn't a Ghost-type move persay, making Alice one of the few gym leaders in pokemon history to do this.