OK hear me out on this one.
Metagross @ Leftovers / Heat Rock
252 HP / 248 Sp.Def / 8 Spe
Careful Nature
- Sunny Day
- Stealth Rock
- Toxic
- Substitute
With Rain teams being so ridiculously prevalent in the current metagame, Metagross can serve as the least expected candidate to let a little light shine through. This Metagross set is designed to lead against opposing Politoeds and support a sun or semi-sun team. The EV spread lets it outpseed any listed Smogon Politoed set besides choice scarf while maintaining special bulk. That and sun will just obliterate the effectiveness of Politoed's water moves. Any game without Politoed, or after winning the weather war, Metagross can is used as the Stealth Rock setter, and a toxic-staller.
Some calcs:
Scarfed Politoed in rain using Hydro Pump: 48.9 - 57.96%
After taking 1 Hydro Pump, Metagross is able to set sun up. Now it looks like this
Scarfed Politoed in sun using Hydro Pump: 15.93 - 19.23%
Now we are able to utilize any of Metagross' remaining moves. Set up SR if needed, Toxic whatever wants to come in (or Politoed, although highly unlikely to stay in), or substitute in order to scout the incoming pokemon (again if Politoed chooses to stay in, the sub will not break and then you are free to Toxic).
Specs Politoed in sun using Hydro Pump: 26.37 - 31.31%
This is a negligible amount after leftovers recovery. After seeing sun come up before Hydro Pump, you can expect a switch. Again, the options of what you want to do are the same as before.
This Metagross is specific to certain teams, namely sun teams that need a surprise side-kick to win a weather war. Although specific, it does fill a unique roll. The surprise factor for this Metagross is absolutely through the roof. If you want to play it even more sneaky, you don't even have to run a full sun team, forget Ninetales, just carry a pure Politoed counter to get it out of the way, have Metagross set up, and let a Chlorophyll user blow holes in your opponent's team. Heat Rock is the preferred item if you go this route.