Call me a child, but if I were a Gym Leader I'd use Dragon Types.
Like most Dragon Gym Leaders, my Gym would be the 8th and last badge.
My badge would be titled Fierce Badge.
Team:
Altaria, lvl 48;
Kingdra, lvl 48;
Salamence, lvl 49;
Dragonite, lvl 50;
Mega-Garchomp, lvl 52.
Rematch:
Altaria...