How do you evolve Eevee into Umbreon in Pokemon Pearl or Diamond?
Put it in the first slot of your party holding a soothe bell. A girl in Veilstone City will massage you Pokemon once a day, so just keep changing the date on you DS. Buy a lot of Protiens etc. Make Poffins of its favorite flavor and make them WELL. Walk around a lot with it in he first slot of you party, every 250 steps or so will raise its happiness a point (more if it is holding a soothe bell). A few rare candies raise its happinness too. Don’t ever let it faint. There are certain berries that will lower stats but max out happinnes, used in tandem with vitamins (carbos, etc.) will raise its happinnness. Also, don’t use bitter Herbal remedies on them. “The Soothe Bell increases the happiness gained from walking around. Put in a situation of a clamped D-pad, connected to a charger and a good night’s sleep, anything will love you by morning and evolve at the next level.