You’ll want to head over to Route 4 or 6 when it is night, because Umbreon is known as the moonlight Pokemon and will only appear during that time. Find an Eevee and, to make things easy use the move False Swipe, as this will lower the health of it until it goes to 1 HP. This means you won’t have to switch out your stronger Pokemon and won’t run into too much trouble when the Eevee uses the S.O.S mechanic. Make sure you have a non-attack move like Leer or Growl so if help doesn’t arrive, you don’t have to cause it to faint. Keep causing any help it spawns to faint until an Umbreon spawns.
You could just capture an Eevee and evolve it to Umbreon to save time and energy, but using the S.O.S mechanic does have its benefits. You’ll have a chance of nabbing one with perfect IVs, you’ll get some EV training in, and this is the only way to capture a wild shiny Umbreon. While it might seem like a lot of work, it definitely does pay off in the end when you can defeat every trainer out there.
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