[@LuckyBlackCat] Yeah, the thing with Gyarados being a rain dancer is the fact that it's your mega so it can't hold a damp rock. It also helps that it doesn't take a move slot to get that rain out there. I'd say give it a whirl if you've got any weak links in the team. I'd also say Pelipper since it got drizzle in this generation (and it can learn stockpile).