You’ve just caught a (probably male) Eevee just outside Cyllage City in Pokemon X or Y . Congratulations! Now, let’s evolve Eevee! It’s at the perfect level, right around level 20, which means it’ll start learning type-specific moves once you make the jump.
Thee thing is, you may not know how to evolve Eevee in Pokemon X and Y. Stones are in different spots, there’s Sylveon to consider. It does have 8 evolutionary paths now.
The good news, 5 out of 8 ways to evolve Eevee are effortless. The rest take a while.
If you want to evolve Eevee into Flareon or Vaporeon, then grab a some from the shop in Lumiose City. It’s across from the elegant boutique. There are fire and water stones for sale.
If you want to evolve Eevee into Jolteon, that’s a bit trickier. I haven’t found a shop that sells thunder stones yet, but found one on Route 10 and one by dowsing in the Reflecting Cave.
For Espeon and Umbreon, keep them in your party. Capture it in a luxury ball, give it a soothe bell to hold, and don’t let it faint. After enough time passes, it will evolve. If that happens during the day, you get Espeon. If it’s at night, Umbreon.
Glaceon and Leafeon are more difficult. You must evolve Eevee near specific stones in the world to get these variations. The Icy Rock is in the Frost Cave near Dendemille Town, while the and Moss Rock is near the Pokemon Village near Snowbelle City.
Finally, there’s Sylveon. To evolve Eevee into its newest form, you must use Pokemon-Aime. First, the Eevee must know a fairy type move. If you’re lucky and caught your Eevee at a lure enough level, it will know Baby Doll Eyes. If not, it learns Charm before level 30. When it’s affection is filled, it’s completely full, and fully ensheathed, you’re set. Level it up while it’s Pokemon-Aime stats are full and when it knows a fairy move, and you’re set!
As far as recommendations go, Jolteon and Espeon are solid. You may want a Sylveon for novelty purposes. While Glaceon is also good, the fact that you have to wait so long to acquire it negates it’s story mode usefulness.