You'll be surprised how much this one works.
Blissey (F)@Focus Sash or Focus Band
Ability: Natural Cure
Nature: Gentle (-Def +Sp.Def) or Calm (-Atk +Sp.Def)
EVs: 252 HP 252 Sp.Def 4 Speed
-Counter: Here's where you use that item. Because of extremely low Defence and extremely high HP, if the opponent walks into Counter they will not live to tell the tale. However, you don't want Defence to be too low or you'll get OHKO'd. And no one likes that.
-Toxic: You can see where I'm going here.
-Protect: You guessed it.
- Softboiled/Wish: If you can get Wish, great. If not, use Softboiled.
So here's my Blissey hope you like her! :D <- Blissey face