Espeon Overview
Espeon got itself one of the best new abilities this gen, which is great because it gives it a niche to use over stronger psychics. It still has a somewhat limited movepool, and with Dark type being so widespread this gen it wont see as much usage as Vaporeon, but its definitely a mon that can hold its own on any team.
Abilities:
Synchronize - an ok ability I guess, allows you to inflict the any status Espeon gains (posioned, paralyze, burn, freeze, stupid, etc) back onto the enemy pkmn. I'd rather not be poisoned, so run its DW ability over this always
Magic Mirror
With this not only can Espy not be hit status attacks, but it reflects those moves right back at the user. It even reflects backs field moves such as Stealth Rocks and Spikes. Essentially, with this ability, the enemy can only use direct attacking moves or boosting moves (meaning this ability is the bane of many Blissey sets). Try switching into a Pranster Thunderous, I garuentee you your opponent will rage quit with their Thunderbro priority statuses/Taunts itself
The Cliche Choice Set:
Espeon@ Choice Specs
Ability: Magic Mirror
EVs: 252 SpA & 252 Spe
Nature: Modest/ Timid
-Physic/Psyshock
-ShadowBall
-Hidden Power (Fighting)/ Hidden Power (Fire)
-Grass Knot
Self explanatory, 1st slots for reliable stab (Psyshock is weaker, but gets a better hit on Special Walls like Blissey), Shadowball for a opposing Psychics. Hidden Power type depends on who you want to hit harder Ferrorthorn (which is currently #1 in usage according to Smogon's servers) or Dark Types not named Scrafty. Grass Knot for...well remember when I said Espeon had a limited movepool? Yeah, Grassknot gets a good hit on Tyranitar & bulky waters that arent Vaporeon, but thats about it. I believe Grassknot 2 or 3HKO's Tyranitar, so chances are you'll lose to most variants anyway, given Espy's low defense
The defensive Espeon:
Espeon @ Light Clay /Leftovers
Ability: Magic Mirror
Nature Modest / Bold
EV's: 252 SpA & 252 Spe / 252 Hp & 252 Def
-Reflect
-Calm Mind
-Psychic/ Psyshock
-Shadowball/ Hidden Power (Fighting)/ Yawn/ Morning Sun
-Reflect for some added Defense, while Calm Mind raises SpD and SpA. Psychic or Psyshock for STAB while the last slot can be used for coverage or to force the switch. Morning Sun can be used for recovery, but gets nerfed if any weather but sun is out.
EspyJump:
Espeon@Light Clay/ Leftovers/ Life Orb/ Petaya Berry
Nature: Modest / Bold
EV's: 252 SpA & 252 Spe / 252 Hp & 252 Def
-Calm Mind/ Work Up/ Light Screen
-Shadow Ball/ Reflect/ Wish
-Psychic/ Psyshock/ Stored Power
-Baton Pass
Boost away with Calm Mind (or Work Up if you plan to pass to a mixed Sweeper), then pass it to something that will sweep with it. Espy and also pass dual screens or wishes if you wish it ( I know, I did that. I'm sorry), but thats better left to other mon's. If your gonna use Espy on a baton pass team (short or long chain) it loves getting passed Shell Smashes (assuming your using white herb) and Quiver Dances (hell it can even take a few dragon dances if you want) With a few boost (+6 I believe) Stored Power and Shadow Ball (assuming some of those passed boost were SpA boosts) can shut down the entire game. The other options are for more reliable STAB and the final slot is dedicated to the method of passing.
The Gimmick Espeon Set:
(Saw this set once, it wasn't unbeatable, just extremely strange. Gonna try to recreate it for you to see)
Espeon@Flame Orb/ Leftovers
Ability: Magic Mirror/ Synchronise
Nature: Impish (+Def/SpA)
EV's: 252 Hp & 252 Def/ SpD
-Swagger
-Power Swap
-Baton Pass/Wish/ Morning Sun/ Return
-Psychic/ Return
Idea is to let the enemy 'mon to get a few Atk/SpA boost then hit 'em with Power Swap. Use Swagger to force an attack boost on a physical attacker, which is easy enough to lure out with Espeon's low Def, then cripple them and leave them confused. Then you can spam Return for decent neutral damage or baton pass the attack boost to another mon. Wish for recovery (or Morning Sun if used on a sun team), while Psychic is for STAB.