Pokémon Fact of the Day! Wild Beldum cannot evolve on their own, so when they wish to grow stronger, hundreds of them at a time will begin forming a swarm I'm dubbing a "Superconductor." In this swarm, a few Beldum will link up, and evolve into Metang, or even a Metagross. You do not want to be in the middle of this swarm, however, as anything caught in it is pummeled to mist, for lack of a better term.