What sort of ideas did you have for gym leaders/E4 members that use a theme, but said motif isn't a common type?

Like for example, I had an idea for a character with a drill motif. It could be the rich heiress of a oil (or diamond) tycoon, who has "drill hair," and has a Beedrill (with mega-stone) a Fearow (holding a Scope Lens), a Rhydon (with Eviolite), and an Excadrill (with Groundium Z).

EDIT: With all the Pokemon there are these days, I also wonder if there could maybe be themes alongside common types, too. Such as a bug-type leader that uses Pokemon based on insects in the Coleoptera order.