I just thought of something for countering. Wide Guard can be used against Explosion, but it's risky if used continously.
In case some of you are wondering, there is a way to get Gravity and Curse on Gigalith:
Probopass + Ferrothorn= Gravity Ferroseed
Gravity Ferroseed + 8 = Gravity & Curse Ferroseed
Gravity & Curse Ferroseed + Gigalith= Gravity & Curse Roggenrola