Pikachu X Reader - My Shiftshaping Dream

You are Y/N, an Eevee with a strange ability to shapeshift into any Pokémon you please. Many people are trying to catch you. You finally find a human you can trust, Ash Ketchum and his partner Pikachu, along with his friends Serena, Clement, and Bonnie. (Specifically belonging to Serena)

You replace Serena's official Eevee
I know sun and moon and Pokémon journeys is a thing btw, its just that X and Y is my favorite so lol