Make sure your umbreon has alot of happiness and lvls up in the night time ( 8.00PM-4.00AM). Give it a soothe bell to increase its happiness and you can also give it calcium, iron,etc. Don't let your eevee faint, make sure your eevee does not get poisoned, paralized or sleep.
By getting EEVEE to a high friendship level at night.
You have to make Eevee really happy while it's is evolving,there is no certain level that will make Eevee evolve.
First, get an Eevee that likes you. Second, go and level it up at night (don't use daycare though) If the Eevee likes you enough, it will evolve into Umbreon, and you will get it's Pokédex data!
You can't catch umbreon to get one have an evee have max friendship and train it while its nighttime it will evolve to umbreon.
If you want Eevee to evolve into Espeon then train it during the day, other way 'round for umbreon (On LGFR you need the National Dex)
Eevee doesn't have a set level to evolve into Umbreon. All you have to do to evolve it is max out its happiness at night. ~KKMG1
you have to level him up at night
Level it up at night
Moonstone
By getting EEVEE to a high friendship level at night.
To evolve Eevee into Umbreon max out its happiness at night. Having it first in your party while holding a soothe bell, having it battle a lot, or feeding it many rare candies are all ways to help it evolve into Umbreon. ~KKMG1
Make your eevee like you as much as it can, then level it up at night. Use a soothe bell if your in a hurry
Eevee doesn't evolve into Umbreon with a stone. Eevee evolves into Umbreon when it is levelled up with high happiness during the night.
Train your Eevee at night and with happiness. It will eventually evolve into Umbreon.
It's Umbreon!! You'll get it when you let Eevee evolve by happiness in the night.
To make Eevee evolve into an Umbreon, you have to level it up with high happiness at night.
You will need to have your Eevee to full Happiness, then level it up at least once during the night to evolve it into Umbreon.