7th gen gimmicky Eeveelution team

[Raphetty]

Espeon @ Leftovers Light Clay
Ability: Magic Bounce 
EVs: 252 HP / 4 SpA / 252 Spe 
Timid Nature 
IVs: 0 Atk 
- Reflect 
- Light Screen 
- Psychic 
- Yawn/Shadow Ball

Sets up screens to help Eevee survive attacks. 

Eevee @ Eevium Z 
Ability: Adaptability   
EVs: 252 HP / 4 Atk / 252 Spe 
Jolly Nature 
- Last Resort 
- Quick Attack/Return 
- Baton Pass 
- Shadow Ball 

Eevium Z allows Last Resort to become Extreme Evoboost, which raises Attack, Defense, Special Attack, Special Defense and Speed by 2 stages. The idea is to Baton Pass this boost to Sylveon or Glaceon.

Sylveon @ Chesto Berry 
Ability: Pixilate 
EVs: 4 HP / 252 SpA / 252 Spe 
Modest Nature 
IVs: 0 Atk 
- Moonblast/Hyper Voice (post bank) 
- Stored Power 
- Calm Mind 
- Rest 

With the boost from Extreme Evoboost, Stored Power is a base 220 power move. The fairy type move allows it to hit dark types. Calm Mind because it synergizes well with Stored Power and Chesto Rest is its only single move recovery option.

Glaceon @ Assault Vest 
Ability: Ice Body 
EVs: 4 HP / 252 SpA / 252 Spe 
Modest Nature 
IVs: 0 Atk 
- Ice Beam 
- Stored Power 
- Shadow Ball 
- Hidden Power [Fire] 

Assault Vest for longevity while sweeping. It will mostly use Stored Power if it gets the boost.

Jolteon @ Choice Specs Life Orb
Ability: Volt Absorb 
EVs: 4 HP / 252 SpA / 252 Spe 
Timid Nature 
IVs: 0 Atk 
- Thunderbolt 
- Shadow Ball 
- Hidden Power [Ice] 
- Volt Switch 

Cleanup, momentum etc.

Vaporeon @ Leftovers 
Ability: Water Absorb 
EVs: 252 HP / 252 Def / 4 SpA 
Bold Nature 
IVs: 0 Atk 
- Scald 
- Ice Beam 
- Wish 
- Protect 

Simple defensive set that provides Wish support.

[SirBlaziken]

Sad part is that the baton pass clause is still in effect iirc.

[SaRo|Rapidash]

Maybe give Espeon Light Clay > Leftovers? It doesn't serve much purpose beyond dual screens as far as I can see, and wish from Vaporeon can heal it, so perhaps worth trying? Also not convinced Choice Specs is optimal for Jolteon - there's so many ground types like Lando-T running around that being choice-locked is exceptionally dangerous - like it will be difficult to call a Volt Switch or a HP when Heatran is in and a Lando-T could switch - shadow ball is safe but if Lando-T is scarfed it could EQ sort of thing? Life orb might be better, but that depends on it crucial KOs are missed - I won't pretend to be an expert on Jolteon, I honestly don't know how powerful a 110 (?) SpA fares, I just fell in the current meta volt switch users prefer Life Orb (generally, not always!)

[Raphetty]

Maybe give Espeon Light Clay > Leftovers? It doesn't serve much purpose beyond dual screens as far as I can see, and wish from Vaporeon can heal it, so perhaps worth trying? Also not convinced Choice Specs is optimal for Jolteon - there's so many ground types like Lando-T running around that being choice-locked is exceptionally dangerous - like it will be difficult to call a Volt Switch or a HP when Heatran is in and a Lando-T could switch - shadow ball is safe but if Lando-T is scarfed it could EQ sort of thing? Life orb might be better, but that depends on it crucial KOs are missed - I won't pretend to be an expert on Jolteon, I honestly don't know how powerful a 110 (?) SpA fares, I just fell in the current meta volt switch users prefer Life Orb (generally, not always!)

Both very good suggestions, updated my original post.

Sad part is that the baton pass clause is still in effect iirc.

I actually didn't know about the change to the Baton Pass clause. Turns out my team is invalid, oh well.

I don't like this rule.. Quiver Dance passing Venomoth is banned, yet a Speed Boost Scolipede passing a boost from a pinch berry is fine. And passing Swords Dance/Nasty Plot to Speed Boost Sharpedo is fine.

[MegaNerd14]

Wtf are you talking about, this "Baton Pass Clause"?  I only play VGC

[SaRo|Rapidash]

Wtf are you talking about, this "Baton Pass Clause"?  I only play VGC

It's a smogon thing - I'm not sure on the specifics, but I think it bans more than one pokemon knowing Baton Pass and also you can't have a pokemon capable of Baton Passing speed + another stat. I really dislike this ban, so I usually just play battle spot for that kind of thing, but w/e.

[MegaNerd14]

It's a smogon thing

I guess that makes sense.  A complaint to smogon, you made your system way too complicated for a kid's game. Yet another reason why they suck