QUOTE(thirty6whoisit @ Feb 21 2017, 05:27 PM)
The naming works once, but there is a theory of guaranteeing getting Umbrion and Espion for evolution once you use up the naming trick. Rumor has it, if you dont and simply just click evolve, you will only get V, F, J only - i.e. no chance of getting U, E.
I have tried nearly 10 evolutions since gen 2 released, none produced E, U through direct evolution. I have yet to use the naming trick.
It turns out it is easier and surer to evolve Espeon and
Umbreon.
Yes, the naming trick works only once. Make sure there is no extra space in the name, and don't use Keyboard of other language such as Chinese keyboard, the character codes may be different.
After that, put your Eevee as your buddy, walk it for at least 10km, then from the buddy screen, touch the candy to invoke the Pokémon screen and evolve it from there. You will get Espeon when you evolve it during day time, and Umbreon during night time. Make sure your Eevee is still your current buddy when you evolve it. I know, because I wasted one good Eevee by evolving it after I swap it out from the buddy system.
For Vapereon, Jolteon and Frereon, it's still by chance.