Gengar Gijinka

In the Reverse Era, a female shiny Gengar, found a Mega Stone, letting her Mega Evolve into her eerie white form, she haunts a cemetery at night, luring unsuspecting humans into a ghostly maze made of twisting bushes, capturing them with reverse PokéBalls. Generations after a comet gave pokemon more humanoid forms, Pokémon evolved to have the hability to switch between their original forms and human "Gijinka" forms, being able to use their powers in both forms. During the great War led by Reshiram, Pokémon reversed-engineered PokéBalls to capture humans, creating the "Reverse Era." Now, humans live with the threat of being trapped in PokéBalls and serve pokemon.