I wouldn't build an entire team around countering it unless you're playing an earlier gen? It can be devastating in earlier gens but newer games have some ways of countering it. It's a very strong wall breaker so you may need to rely on chip damage and playing around it's coverage moves. If it doesn't have shadow ball you can switch into Lunala and Calyrix(shadowrider) otherwise you may want to instead try dark types with a strong "Sucker Punch" to revenge kill it with priority. Both options are fairly standard on Ubers SwSh teams if I'm not mistaken.