Buy a Thunder Stone on the 4th floor (or, if you're not into turning your Eevee into a Jolteon), get a Water Stone or Fire Stone.
He will give you TM 18 - Counter - for free! Here are a few things you should definitely do while in the store: The sheer amount of stuff you can buy in this giga-sized Pokémon Mart. If you've got a lot of cash to burn, this is definitely the place to be. You can easily win multiple Eevees by completing the Gym Leader Castle mode in that game.
Players who want to get all three evolutions AND still keep an Eevee should grab a copy of Pokémon Stadium for Nintendo 64. Sadly, you can only find one single Eevee in this game. The vote for best evolution goes to the insanely fast Jolteon but all three are great additions to your team. With the help of three mysterious stones, you can evolve Eevee into another, even more powerful Pokémon: Sneak into the building through the back door and you will get your hands on one of the coolest Pokémon in the game: Eevee. But there's a much better secret slumbering in this mansion. What will you get? A certificate, of course. You'll be told to return once you get all 150 Pokémon. Inside Celadon Mansion, the large building in the north, you can talk to virtual members of the Game Freak team. Have you ever dreamed of meeting the people that programmed Pokémon? Here's your chance - at least kind of.
