Want a sleek, Dark-type addition to your Pokémon team? Evolving Eevee into Umbreon is easier than you think! This nocturnal wonder requires a strong bond and a little patience.
First, max out your Eevee's friendship level. This can be achieved through battling together, feeding it berries, and generally keeping it happy. You can usually check friendship levels in-game with a specific NPC.
Here's the crucial part: Evolve Eevee at NIGHT. If you evolve it during the day with high friendship, you'll get Espeon instead. Make sure it's nighttime in your game world before triggering the evolution. No special items are needed, just pure, devoted friendship under the moonlight. Embrace the darkness, and welcome your new Umbreon!