Espeon is amazing in pokemon reborn, with 130 SpA and 110 Spe, it can OHKO a lot of things, a simple set would be
-Psychic
-Shadow Ball
-Hidden Power Fighting
-Morning sun
(Or whatever move, Espeon has poor defenses so it'll probably take more damage than morning sun will heal)
You could also use Sylveon, it's a really good eeveelution that can act as a tank. (I prefer Sylveon over Espeon)
My set is:
-Moonblast
-Hidden Power Ground
-Shadow Ball
-Draining Kiss (Great Recovery)
you could also rock out with: Light screen, Trump Card (With Pixilate), Misty Terrain (for Moonblast boost)