I have seen this used with great success:
Umbreon (hardy nature, 252 defense, 252 sp. defense, 6 HP)
double team
wish
substitute
baton pass
The goal is to survive long enough to get 6 double teams off, a substitute up, and to pass a wish to your next pokemon. Passing to almost any pokemon makes it nearly invinsible. However, this set has NO offensive capabilities and is easily foiled by a hazer or whirlwind/roar.
Umbreon (hardy nature, 252 defense, 252 sp. defense, 6 HP)
double team
wish
substitute
baton pass
The goal is to survive long enough to get 6 double teams off, a substitute up, and to pass a wish to your next pokemon. Passing to almost any pokemon makes it nearly invinsible. However, this set has NO offensive capabilities and is easily foiled by a hazer or whirlwind/roar.