Venomoth (F) @ Sitrus Berry
Ability: Shield Dust
EVs: 252 SAtk / 60 SDef / 196 Spd
Timid Nature (+Spd, -Atk)
- Skill Swap
- Sludge Bomb
This relies more on your opponents Things, than yours almost.
Sludge bomb is powerful STAB and Psychic is power Coverage, that gets that out of the way.
Now you have a Sitrus Berry when your Hp starts to get low, and then you can steal whatever item your opponent has. Skill Swap gives your opponent Shield Dust, if you feel their Ability is more usefull to you.