So, I've been playing through Y again recently, and just reached that route between Lumiose and Camphirer town. After doing a little bit of level grinding and starting to push through the route, I ended up running into a shiny Gulpin (not a hoard, just a standalone Gulpin). Quite an unexpected surprise. Initially wasn't planning on even batting an eye to Gulpin, but since random shinies usually collect dust in my boxes behind the RNGs/TSV shinies, I decided to put this stroke of luck to use and use the Gulpin on my in-game team. He might be a surprising MVP on my team, and the fact that he's Modest doesn't hurt either.