Protect first to see what move my opponent would get locked into. Then Use counter/mirror coat. Earthquake makes sure you arent taunt bait, and can hit stuff that is weak to it. Rindo berry lets you survive unSTAB's grass attacks like infernape grass knot. Actually, with the given evs (my pert had a 30 iv in HP, if that makes a difference), swampert survives all attacks outside of STAB grass attacks. The defense evs let it survive a jolly LO breloom's spore because it got lazy and didnt spore first. The SpD evs let it surviv choice specs modest salamence draco meteor. The only attacks that kill it are STAB special grass attacks and modest Specs Porygon z Hyper beam. Protect lets it beat potential mixed attackers and slaking, whose giga impact KO's otherwise.
The only problem is sleep abusers, grass types, and stat uppers. And physical ghost types like shedinja who counter cant hit. Most special dark types aren't a problem (houndoom and spiritomb get beaten by EQ I think)