I've only ever encountered one shiny, a Swablu, and of course it was my second encounter on a route during a nuzlocke. A friend suggested I should add shiny clause just for that encounter, so I did simply because it was my first ever shiny (other than the Red Gyarados, of course). I then sent it out against a wild Pokemon, and it immediately died/fainted to a crit. And, well... let's just say there was a lot of raging involved after that. My luck sucks ;.;