Ok, there are a lot of swampert sets here. But every set had something incorrrct in it like a calm nature physical tank swampert.
Swampert @ Leftovers
Ability: Damp
EVs: 252 HP / 8 Def / 248 SpD
Careful / Sassy Nature
- Stealth Rock
- Flip Turn
- Earthquake
- Toxic / Scald
This set is pretty self-explanatory. Swampert is a reliable to stealth rocker due to it's good bulk and lack of weaknesses. Leftovers is the most obvious item, though it can be changed for Rocky Helmet or Rindo Berry. The EVs make it a Special Tank with a Sp. Def boosting nature. Flip Turn is to pivot out and give a switch to swampert's offensively minded teammates after it sets up rocks, additionally swampert can use minimum speed for lowest speed possible for the slowest flip turn. Earthquake is obvious STAB threatening Pokemon weak to it and still hitting quite hard due to swampert's high attack and earthquake's great 100 Base Power. Toxic is nice for crippling switch ins and other offensive Pokemon although it can be exchanged for scald which has a chance to burn, more damage, does not miss and burn cripples physical attackers. Like all swamperts, it hates grass types. Spam toxic and flip turn once you set up stealth rocks. Make setting up stealth rocks you primary priority.