The only way to get an Espeon in FR/LG is to trade you Eevee over to trade it over to RSE
and level it up with Maximum happiness after noon and before midnight.

You get the eevee. But you trade it to ruby,sapphire,or emerald and you raise it when its
morning time. You keep on holding it
in your party. YOU NEVER PUT THE EEVEE IN THE PC OR IT MAY RUIN IT!!! Raise it till it
loves you and it will evolve!
Its usually takes a long time but, its worth the wait!

use the water stone

use some mushrooms from mario world