Marshadow plays a key role in Pokémon: Kimi ni Kimeta! as a shadowy guide figure. According to the film's lore, Marshadow appears to those chosen by Ho-Oh to become the Rainbow Hero, essentially serving as their supernatural mentor. The Pokémon also has an important failsafe duty: if the Rainbow Wing that marks the chosen one ever loses its color, Marshadow is responsible for sealing it away.
Content compiled by AnimeList.moe from publicly available sources.
