Shadow Pokémon are the one of the special variant in Pokémon Vortex. These Pokémon are immune to status effects. Shadow Pokémon are 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 5 and 20. Shadow high leveled Pokémon can be caught on maps at any level between 35 and 46. Shadow legendary Pokémon can be caught on maps at any level between 50 and 75.
In the most recent version of Pokémon Vortex, all Pokémon including Generation VII Pokémon were introduced in all 6 variants.