My current core, which causes quite a lot of rage! It's very hard to stop a team built around tailwind if you don't predict almost every turn correctly (you basically want to get the full 3 turns out of tailwind, ie using only just before you faint), on the flip side I can lose with a landslide if I get outpredicted very well.
Whimsicott @ Leftovers
Trait: Prankster
EVs: 252 SAtk / 252 HP / 4 SDef
Modest Nature
- Giga Drain
- Tailwind
- Hidden Power [Fire]
- Taunt
When combined with
Kyurem-Black @ Choice Band
Trait: Teravolt
EVs: 252 Spd / 252 Atk / 4 SDef
Adamant Nature
- Outrage
- Dragon Claw
- Fusion Bolt
- Hidden Power [Fire]
Gives a very potent late game sweeping combo. Whimsicott also counters the two most common volt turn members and having a Keldeo check and a way to deal with pokemon like Jellicent and politoed is awesome. HP fire eliminates Scizor which is the #1 target for the core to be able to deal with.
roles: Early game whimsicott usually pops out to taunt SR users and lure/ko pokemon like ferrothorn/forretress/scizor. If its still alive for the late game its used for the tailwind. Kyube is a hole puncher early game if applicable, otherwise it gets 2-3 ko's late game or mid game with the boost of the tailwind.
Haxorus can replace Kyurem for banded EQ (excellent alternative late game sweeper) whilst Tornadus can replace whimsicott for tailwind. I've used all four before as well but the weaknesses begin to stack up and its difficult to support a four core, I ended up getting to only 1846 with all four, but with just one tailwinder and 1 outrager with a few other pokemon to take advantage of the benefits, I've gone as high as 1960 :)
For those wondering why I don't use a pokemon like Heatran, Nidoking, Landorus or Terrakion, its because banded outrage is so strong you can't really "predictably" switch around it, barring switching in with steels. Gyarados and Volcarona work well with the core though because they can snowball with set up moves if you try switching around too much.
edit: I still use pokemon like Terrakion on my team, if they are decent out of the tailwind they're fine, they're just not the primary recipient of tailwind.