My forretress has an impish nature, 252 HP evs, 252 defence evs and 4 sp. Defence evs. Its moves are: Stealth rock Toxic spikes Spikes Explosion/rapid spin
Rapid spin. Forretress can spin away hazards, set up its own and be a good physical wall. It would be a shame if you just threw it away. And I suggest using Gyro ball instead of toxic spikes, just so you have some offensive power.