Introduction: I really like rain dance teams and I think they have a lot of potential to work well even if the whole team isn't based on rain dance. The ability to blatantly outspeed the opposition is incredibly useful and the delicate nature of the battle (hinging often on the first few moves) is really exciting. Although I've made a few attempts at rain teams this is the first one I have made that covers almost everything I wanted my team to cover when I envisioned it.
Team at a glance:






The Goal: To set up rain and sweep as fast and efficiently as possible.
In Depth:
The Lead

Azelf @ Damp Rock
Ability: Levitate
Nature: Naughty
EVs: 252 SpA / 252 Spe / 4 HP
-Stealth Rock
-Rain Dance
-Psychic
-U-turn
Overview: I had a lot of choices for a rain dance lead. I wanted to be able to get Stealth Rock up to help with the sweep, so that gave me a smaller pool of choices. I didn't want to be simply shut down by a taunt so I something that could get the job done the majority of the time. This worked out. Damp Rock, Stealth Rock, and Rain Dance are obvious. Explosion is always a useful move but I didn't want to give up Azelf right away so I needed U-turn on the set. That explains the EVs and nature. My main goal is to stealth rock first, faking a focus sash set, then rain dance, and then U-turn out. Later I will either set up rain dance one more time, explode, or do both.
The Mixed Sweeper

Kingdra (M) @ Life Orb
Ability: Swift Swim
Nature: Naughty
EVs: 252 Atk / 240 SpA / 16 Spe
-Waterfall
-Hydro Pump
-Draco Meteor
-Outrage
Overview: Kingdra is the mixed sweeper on my team. He is the only swift swimmer in OU and is simply an overall powerful force on the team. A Naughty nature is standard fare for fast mixed sweepers. 16 Speed EVs guarantees that he will outspeed Timid Choice Scarf Heatran in the rain. I put Rain Dance over Dragon Dance for the primary reason that my team needs more rain dancers, and Kingdra is bulky enough to pull it off, and second Dragon Dance would only boost up one of my attacks and give me speed that I probably won't need. Hydro Pump is a devastating special STAB attack in the rain to take out physical walls like Skarmory and Draco Meteor is an obvious choice on a mixed sweeper set.
The Special Sweeper

Ludicolo (M) @ Life Orb
Ability: Swift Swim
Nature: Modest
EVs: 252 SpA / 252 Spe / 4 Def
-Hydro Pump
-Ice Beam
-Grass Knot
-Rain Dance
Overview: Ludicolo is my special sweeper. He has a modest nature for maximum damage and his EVs are designed for outrunning as much as possible while doing as much damage as possible. Surf and Ice Beam are obvious choices. Between Grass Knot and Energy Ball I had some trouble deciding. Grass Knot seems way more useful than Energy Ball in every case except against Vaporeon, where I'll end up getting forced to switch out. I'm not really sure which decision is best but I went with Grass Knot to get more OHKOs and damage against everything except Vaporeon. Rain Dance is, once again, because I need as much Rain Dance on my team as I can get considering I have one suicide damp rock rain dancer and one very iffy damp rock rain dancer. Switching Rain Dance with Energy Ball is considerable although that would lead me with very little rain.
The Physical Sweeper

Kabutops (M) @ Life Orb
Ability: Swift Swim
Nature: Adamant
EVs: 80 HP / 252 Atk / 176 Spe
-Swords Dance
-Waterfall
-Stone Edge
-Aqua Jet
Overview: Normally I want to send in this one after Bronzong does his bidding. After Bronzong my opponent will have endured two exploders, possibly one hypnosis, and two rain dance sweepers. That's where Kabutops comes in to Swords Dance and end the day. 176 Speed lets me outrun base 70s outside of rain, and in rain there isn't much to worry about in terms of speed. Stone Edge has horrible accuracy but does a ton of damage and adds good coverage. Considering it isn't a move I will likely have to use often I feel the risk isn't too much to bear. I chose X-Scissor over Aqua Jet for a couple reasons. First of all I would hate to have to use Stone Edge to fight against grass type pokemon. X-Scizzor kills them where they stand. Second the priority of Aqua Jet isn't going to be particularly useful considering I'm going to most likely have 8 days of rain from Bronzong to work with . Scizor is a bit of a worry, whom gets neutral damage on this set with Bullet Punch. I ran the damage calculation and assuming I don't endure too much damage initially (like when I set up SD...) I should be able to take one hit and deliver the OHKO in return. On the other hand if I used Aqua Jet then I would be able to OHKO Scizor if and only if Scizor endured a little bit of damage earlier in the game (assuming a Choice Band set). Floatzel may be a better choice for this team slot but lacks the sheer power of Kabutops. I could consider lowering the Speed EVs to add more HP EVs if I'm primarily planning to run him in the rain, but overall I don't think it's that necessary.
Middle Game Dancer / Support

Bronzong @ Damp Rock
Ability: Levitate
Nature: Relaxed
EVs: 252 HP / 128 Atk / 128 Def
-Rain Dance
-Gyro Ball
-Hypnosis
-Explosion
Overview: Impish nature for more defense. Rain Dance will cover my fire weakness and set up 8 turns of rain for finishing off the sweep. Reflect is useful to support the team and let Bronzong last longer against physical threats, although I don't like the idea of leaving my final sweeper wide open to special threats, but that can be remedied to an extent with the use of Dugtrio. Hypnosis has bad accuracy but if I do put an opposing pokemon to sleep then that pokemon is virtually KOed because it will die in the final sweep. That is why I chose it over Light Screen or some other support move. Explosion is the last choice and an obvious one. With 128 Atk EVs I can OHKO Snorlax with Explosion. Bronzong's role is very simple and supports my team well.
The Revenge / Support

Dugtrio @ Choice Band
Ability: Arena Trap
Nature: Jolly
EVs: 40 HP / 252 Atk / 216 Spe
-Earthquake
-Stone Edge
-Night Slash
-Aerial Ace
Overview: First of all, Dugtrio is essential to eliminate many threats to my team. Choice Band over Life Orb for the OHKO on Tyranitar. 216 Spe EVs lets me outrun base 115 Speed pokemon and 40 HP EVs lets me survive a Lucario Extreme Speed so I can OHKO. I still can't switch into Lucario if it swords dances as I switch though...so it's a bit of a far fetched scenario but could come in handy. I'm thinking 252 Spe EVs might be best so I can speed tie Alakazam which would probably threaten to kill my team more often than a predicted Lucario switch. Anyways about Night Slash over Sucker Punch. Honestly I just don't like Sucker Punch. People just set up and outspeed me and kill me and it gets ugly. This leaves me vulnerable to Alakazam. A complete counter would be Alakazam with Calm Mind since not even Sucker Punch could take it out. Anyways Dugtrio kills a number of threats like Tentacruel, Blissey, and Tyranitar, so he is essential, but his moves/nature/EVs might be changed.
Any advice would be really appreciated. Thanks.