What are Wobuffet's weaknesses?

Answer 1

Since Wobuffet make up for low Atk and Sp.Atk with higher Def. and Sp.Def, its best moves are Counter and Mirror Coat, so you can use the weather and status inflictions to easily put Wobuffet out of commission.

For example, your Shuckle can use Toxic, Wrap, and Sandstorm to weather Wobuffet's HP to dust.

Or, after Wobuffet uses Counter or Mirror Coat, use Disable so you can unlock a gateway for firing either your physical or your special attacks for as long as either Counter or Mirror Coat is Disabled.

You can also use Torment for the same purpose, or you can use Taunt to render Wobuffet as powerful as a veteran Magikarp.