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)