Jolteon @ Bright Powder
EV's: 252 SpA / 252 Spd / 4 Hp
Strategy: Start with substitute, and use it until your opponent misses or doesn't attack you. With a substitute to cover your low defenses, use Thunderwave to paralyze the enemy to lower their chances of being able to hit you. Then use Double Team multiple times, until you're confident that you will not be able to be touched. You're then clear to use thunderbolt. Even though this moveset only has one damaging move, Jolteon with high SpA EVs is easily strong enough to take down most Pokemon that can resist thunderbolt. If the substitute fades, simply just use it again (unless you're low on hp, just rely on your double team and your opponents' reduced accuracy.
- replace Thunderwave with Shadow Ball for more type coverage, incase you come up against any ground or steel types.
- replace Thunderwave with Baton Pass to pass on your substitute and double team effects onto another party member
This works pretty well in my opinion, and I've been using it for a couple of weeks now with great success. Hope it helps though... :)