Shadow Pokémon are the one of the special variants in Pokémon Vortex. These Pokémon are immune to status effects. Shadow Pokémon are as rare as every other Pokémon that isn't Normal Variant.
All of these Pokémon were made by staff of Pokémon Vortex. Shadow basic Pokémon can be caught on maps at any level between 6 and 18. Shadow rare Pokémon can In the most recent version of Pokémon Vortex, all Pokémon including Generation VII Pokémon were introduced in all 6 variants.
Shadow Pokémon have the same colors as Shadow Lugia from Pokemon XD: Gale of Darkness.