Set: ChestoRest Politoed

Politoed @ Chesto Berry
Trait: Drizzle
EVs: 252 HP / 252 Def / 4 SAtk
Bold Nature (+Def, -Atk)
- Scald
- Toxic
- Perish Song
- Rest

Politoed tends to run some pretty offensive sets, which are great for damage output but relatively poor for survivability. Although not too different from Politoed's standard defensive set, ChestoRest is an interesting idea that has a few advantages when it comes to maintaining your choice of weather.

The most important thing a ChestoRest set provides is what is essentially a second life. This is most helpful when Politoed gets hit by a status ailment, since it can just be healed off. Depending on which ailment it took, a standard Politoed could have been crippled for the match. 

Defensive Politoed doesn't need extra type coverage, so a mono-attacking support set is adequate. Scald remains a decent method of checking threats like Gliscor and netting burns. Toxic is generally the best option for hitting switch-ins like Jellicent or Gastrodon. Perish Song has a more specialized use, but it can be crucial against a last-minute stat booster. Rest should be saved for when Politoed is about to faint; usually one use is enough for Politoed to keep up Rain long enough.

Since ChestoRest is a defensively-oriented set, Politoed's teammates should generally fit the theme as well. A more stall-based approach to Rain is viable, with teammates like Ferrothorn providing hazard support. Rain Stall is one of the most effective team archetypes around, and this set does a good job of providing for it.