I know the franchise only by reputation, but I have seen the trailer in question. I feel like Grass-types get left out of these things not so much because of any sort of systematic prejudice as because most of them are neither particularly iconic (like Pikachu and Jigglypuff) nor particularly badass (like Lucario and Greninja), which is unfortunate, but kind of understandable. Still, I feel like Grovyle would fit right in…
