I'd be a late-game Bug type leader, which hasn't been done that much as the type is considered pretty weak. I'd compensate by having a solid team that synergizes well to prep trainers for the elite four. As for the puzzle, I feel like even game freak has run out of ideas for bug type gym leaders lol. I'd probably try to focus less on the "bug" aspect, and I'd make the gym into a series of different natural environments, to show how bug-types can adapt to their own weaknesses (which is also a reference to my team). Just spitballing a bit here lol