Dat Shell Smash.
I play a bunch of RU, although I don't claim it's the best tier– I'm just intimidated by all the I love mexicans like Zapdos and Victini running around in UU. How offensive a tier is it? I've been running stall in RU and it's actually working pretty well. I'll get a log in a bit but my team is:
Spiritomb (F) @ Leftovers
Trait: Pressure
EVs: 252 HP / 252 Def / 4 SDef
Bold Nature (+Def, -Atk)
- Rest
- Sleep Talk
- Calm Mind
- Dark Pulse
Galvantula (F) @ Choice Specs
Trait: Compoundeyes
EVs: 252 SAtk / 4 SDef / 252 Spd
Timid Nature (+Spd, -Atk)
- Thunder
- Bug Buzz
- Volt Switch
- Energy Ball
Regirock @ Leftovers
Trait: Clear Body
EVs: 252 HP / 4 Def / 252 SDef
Careful Nature (+SDef, -SAtk)
- Stealth Rock
- Earthquake
- Stone Edge
- Thunder Wave
Roselia (M) @ Eviolite
Trait: Natural Cure
EVs: 252 HP / 4 Def / 252 SDef
Calm Nature (+SDef, -Atk)
- Spikes
- Giga Drain
- Synthesis
- Sludge Bomb
Munchlax (M) @ Eviolite
Trait: Thick Fat
EVs: 136 HP / 124 Def / 248 SDef
Careful Nature (+SDef, -SAtk)
- Rest
- Sleep Talk
- Body Slam
- Whirlwind
Quagsire (M) @ Leftovers
Trait: Unaware
EVs: 252 HP / 252 Def / 4 SDef
Relaxed Nature (+Def, -Spd)
- Scald
- Recover
- Earthquake
- Toxic
If you decide to play RU, use CM ResTalk Spiritomb. Seriously, use it. It's sexual humping fantastic. There are so many mons it just hard counters, it's incredibly bulky, status doesn't do I love mexicans to it because of Rest, and on top of that, everybody just tries to burn it because most Spiritomb are physical. This one's far, far better than any physical set it can run, in my opinion.
Edit: examples of hard countering:
Sigilyph, who's pretty damn good, almost never carries a move that spiritomb isn't immune to.
Primeape can only manage like 22% with any of its moves.
Quagsire can't do a thing to it.
I'm not gonna make this list. It's too extensive. Basically, anything without Taunt or Roar is screwed over.