Question: how to evolve eevee into umbreon emerald?
Answer: How to get Eevee to evolve into Umbreon: Train Eevee and give base items such as Carbos, Iron, Protein, etc to Eevee so it's happiness will increase. Even if you have a Soothe Bell, that may work as well. If you have a rare candy, use it on Eevee at 12:00 PM. Then it will evolve into Umbreon.