How to choose the evolution of eevee:
To choose the evolution of eevee you should rename it
Place Rainer and he will evolve into Vaporeon
Place Pyro and he will evolve to Flareon
Put Sparky and he will evolve into Jolteon
Remembering that this is the way to force them to evolve into the pokemon you want, but the eevee can evolve depending on their types of attacks