Shedinja is a difficult Pokémon to get at the best of times, but in Pokémon Go, it’s nearly impossible to find one unless you play the game during certain key events.
Unlike in the main series, where you need to evolve a Nincada into a Ninjask to get a Shedinja to spawn, Niantic has locked Shedinja through specific methods, making getting its shiny form nearly impossible.