I tried to be creative, but im not that good of a battler D: Please rate!
I lost too... but thats probably because Mew is super good!

Espeon (F) @ Light Clay
Trait: Synchronize
EVs: 252 HP / 4 Def / 252 SDef
Sassy Nature
IVs: 0 Spd
- Light Screen
- Trick Room
- Reflect
- Psychic

Umbreon (M) @ Leftovers
Trait: Inner Focus
EVs: 4 HP / 252 Def / 252 SDef
Careful Nature

Jolteon @ Lagging Tail
Trait: Volt Absorb
EVs: 4 HP / 252 SAtk / 252 SDef
Quiet Nature
- Thunderbolt
- Volt Switch
- Shadow Ball
- Hidden Power [Ice]

Leafeon (M) @ Leftovers
Trait: Leaf Guard
EVs: 120 HP / 252 Atk / 136 SDef
Brave Nature
- Leaf Blade
- X-Scissor
- Baton Pass
- Curse