Leaked Pokémon GO update files suggest that Shadow Pokémon will soon be arriving on the app, and they'll need to be purified.

On the surface, we often wonder how free-to-play games are effectively the biggest and most profitable titles in gaming right now. The likes of Fortnite and Pokémon GO are leaders of the genre, and understand how to pull in the profits. The key is obviously to keep people interested. Roll out a free game and leave it dormant, then people will soon head elsewhere. Niantic certainly hasn't done that with Pokémon GO.

Although no one could have predicted how popular Pokémon GO was going to be for the first few months of its existence, Niantic knew that interest would soon wane, and the player count would drop. That gave the developers a few months before they had to start rolling out big updates and making improvements. In the past year, Niantic has been doing that more than ever, hence the resurgence in the game's popularity.

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Trainers are so eager to find out what's next for Pokémon GO that they've gone mining through its data. The latest discovery has revealed that "purified Pokémon" will soon be debuting in-game. Those of you who played Pokémon Colosseum on GameCube will know that the existence of Purified Pokémon implies the existence of Shadow Pokémon.

As you might have guessed, even if you didn't play Colosseum, shadow Pokémon are bad news. In the game, they are used for evil purposes by Team Cipher. Once captured by a trainer, it is their job to level them up and purify them. That makes them perfect for Pokémon GO. Trainers could be tasked with capturing shadow Pokémon, whether it be in the wild or through raids, and then have to walk with them as their buddy in order to purify them.

For now, this is all speculation, of course. Even if the purified Pokémon comment in the update does signify the imminent introduction of shadow Pokémon to Pokémon GO, who knows how long we'll have to wait for them to arrive? Plus, there's also the chance that the idea is scrapped altogether before it ever reaches the game. Keep an eye out for updates though, as sometimes Niantic rolls out new features without telling anyone.

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