In Pokémon X and Y, Espeon evolves from an Eevee. In order to evolve, Eevee’s friendship stat needs to reach its maximum during the day. If Eevee evolves at night, it becomes an Umbreon instead.
- Catch a wild Eevee with a Luxury Ball
In Pokémon X and Y, Eevee is found on Route 10 in the grass. Catch it with a Luxury Ball to make its friendship stat higher from the moment it is captured.
- Give Eevee a Soothe Bell
Let Eevee hold a Soothe Bell to increase its friendship and happiness levels over time.
- Keep Eevee in the party
In order to maintain Eevee's friendship levels, keep it in the party, even if it is not in use. Placing Eevee in the PC causes its friendship to drop significantly.
- Battle with Eevee
Eevee's evolution takes place once it levels, provided its friendship level has reached its maximum. In order to do this, Eevee must be placed in battle periodically. This allows it to gain the periodic experience it needs to level up.
- Ensure Eevee evolves into Espeon
Because Eevee evolves once it levels up, and its friendship is maxed out, there is a chance it may evolve at night. Either battle with Eevee only during the day, or press the B button if it tries to evolve at night, to ensure it evolves into an Espeon.