So I've had an account on here for years now and I've never posted anything so I figured I might finally post my UU rain team that I've had for a very long time. It's been a great and fun team and has actually beaten its fair share of OU teams. Many people have wanted to know all the key components, surprises, EVs, movesets, etc. to this team for awhile, so I figured I might as well post it to help others and to maybe get some CnC to make this team even better.
As for the title, the peak 13?? thing is because I don't know how high this team has peaked. My account I normally use on PO was banned on the Smogon server, so whenever I wanted some UU laddering I made up some dumb name to get in and play. Usually on the rare times I came in to play UU, after about 30-ish minutes I was one of the top players online at the time (more people really need to play UU) so this team could never get into the 1400s; the highest it's ever gotten was just barely in the 1300s and I don't remember the exact number.
Anyways, like most teams, this team has gone through tons of changing (this final team is the 8th version).
The team-building process...
Version one was mostly a test to try out the idea of a UU rain team. The thought of Swift Swim Kingdra dominating a metagame without permanent weather sounded pretty cool to me, but I didn't know where to begin for compliments. In this version, Machamp was near useless and Kabutops was only useful when their was rain. So if Volbeat died, it felt more like 2 Pokemon died.
Volbeat sucked so I tried a weird Uxie set with Rain Dance/Memento/Stealth Rock/U-Turn. It didn't work out well. Rotom-H was a complete experiment and I replaced Flygon with Cobalion just as an experiment to see how good it is since it appealed to me on paper.
I put Volbeat back and decided to try Weavile and Darmanitan as revenge killers. But even without the rain, Darmanitan didn't do what I wanted him to and Weavile just didn't fit the team at all.
Again I tried experimenting with new compliments for the team. I chose Escavalier since lowering his fire-weakness with rain sounded like a a good idea at the time. Sheer Force Thunders from Nidoking sounded too good to pass up, but he did not perform the way I had hoped.
I tried out Hitmontop as a revenge killer and Snorlax as a wall. Snorlax worked okay enough to survive this version, but Hitmontop didn't.
I decided that I should try out Flygon again as a revenge killer instead of Hitmontop. This team worked out pretty well for awhile, not gonna lie, but it had a few glaring weaknesses (Heracross, anyone?) and I knew I could make it better.
Azumarill worked perfectly as a revenge killer. With rain it was sensational, capable of OHKOing just about anything that had some damage done to it. Without rain, it still hit like a fucking monster and works well as a clean-up Pokemon. While losing Kabutops's Swift Swim put me down a bit, the bulk and sheer power of Azumarill made me wonder why I never used it before. As for Cobalion, I thought this team needed a fighting type and a steel type so voila, Cobalion. I was surprised at how well it worked, the guy was capable of completely shredding unprepared teams and he's a great switch-in and set-up Pokemon.
The team:
Black Widow - Sableye @ Damp Rock
Trait: Prankster
Careful nature (+SpD, -SpA)
EV's: 252 HP, 120 Def, 136 SpD
Rain Dance
Recover
Will-o-Wisp
Confuse Ray
Sableye is a fantastic Pokemon. This set makes it much worse than most since it loses Leftovers for Damp Rock and it loses Foul Play, Taunt, or another move for Rain Dance, but it still works fantastic. Ghost/Dark obviously gives it no weaknesses and the Normal, Fighting, and Psychic immunities are incredibly helpful. All of its priority moves help a lot, making it a good counter to many threats and can let me stall for a few turns if necessary. The only thing she hates are Taunt and Heracross. Taunt makes her completely useless and gives the opponent a turn or two to set up. As for Heracross, he's probably about the biggest threat to this team so it's not too surprising he threatens Sableye. However, Sableye can set up rain and let Azumarill or Kingdra kill Heracross, or I can pray I get lucky and just confuse Heracross hoping it hits itself a turn or two in a row as I switch out.
Captain America - Kingdra @ Life Orb
Trait: Swift Swim
Naughty nature (+Atk, -SpD)
EV's: 252 Atk, 24 SpA, 232 Spe
Dragon Dance
Outrage
Waterfall
Hydro Pump
This guy's pretty much the main sweeper of the team and is one of the main reasons this team is so successful. Honestly, I think the good 'ol Captain has died more often from Life Orb damage than an actual attack. In rain he hits an unrivaled speed stat and the boost to Waterfall and Hydro Pump makes him nigh unstoppable. Dragon Dance is there when either there's no rain around or they switch in something that I can set up on, like a Bronzong. Outrage and Waterfall are the main STABs, but Hydro Pump is there to get rid of physically bulky walls and it has caught many people off-guard. This guy even lets me beat some OU Drizzle teams thanks to permanent Swift Swim.
Hulk - Azumarill @Choice Band
Trait: Huge Power
Adamant nature (+Atk, -SpA)
EV's: 252 HP, 252 Atk, 4 Spe
Aqua Jet
Waterfall
Return
Superpower
You may laugh, but this guy's called Hulk for a good reason. 654 attack is fucking godly and 404 HP is nothing to scoff at. Aqua Jet is almost always the move he'll use, since base 60 priority coming off of 654 attack in the rain spells gg. Waterfall is there when there's something slower like a Snorlax or if I know they're gonna switch. Return is basically only there in case I see a Slowbro or something that resists Water, Fighting, and Ice (I chose Return over Ice Punch). Lastly, Superpower is a pretty fitting move since the team names are based on the Avengers, but it's mostly a last-resort move or to hit something harder than Aqua Jet.
Iron Man - Cobalion @Leftovers
Trait: Justified
Jolly nature (+Spe, -SpA)
EV's: 4 HP, 252 Atk, 252 Spe
Stone Edge
Close Combat
X-Scissor
Swords Dance
He's a steel type so he's close enough to Iron Man, I suppose. This guy's a great counter to the UU dragons as well as Psychics, Darks, and others. There isn't much I can think to say about him. I Swords Dance when I can set-up on something such as an Umbreon or Flygon stuck in Outrage and proceed to sweep from there. 346 speed is pretty good in UU and he's bulkier than many expect with Leftovers so he can keep up a fairly long sweep. He's a bit like a mini-Terrakion (my fave Pokemon in OU) with a better defensive typing. Cobalion and Sableye are pretty much my defensive core. Yeah, I'm just rambling, Cobalion is a good switch-in and can be deadly if he can set up an SDance or two.
Thor - Raikou @Life Orb
Trait: Pressure
Rash nature (+SpA, -SpD)
EV's: 4 HP, 252 SpA, 252 Spe
Aura Sphere
Weather Ball
Thunder
Extrasensory
Ugh, I wish so much that the event Raikou was Timid. Really, the Rash nature is pretty much the main thing that brings him down since his speed takes a pretty big hit, preventing him from being as dominant as he should be. In most of the previous versions of this team, he was the event version and in a few I tried regular Raikou. Aura Sphere and Weather Ball were too sweet of gifts for me to give up for the extra speed. Extrasensory is kind of a filler move, but I don't think replacing it with HP Ice would help too much. But honestly, Thunder, Weather Ball, and Aura Sphere give him great coverage and power. Seriously, Thunder OHKOs or 2HKOs tons of UU Pokemon and Weather Ball is pretty nasty in the rain. Raikou at times can seem like the strongest member of the team and he can sometimes seem like the weakest. I really want to cheat and change his nature to Timid so he'd be fantastic, but I'm too nice of a guy to do that. He's a bit inconsistent depending on the team I face, but he still hits like a nuke and has single-handedly swept many a team.
Hawkeye - Flygon @Choice Scarf
Trait: Levitate
Adamant nature (+Atk, -SpA)
EV's: 4 HP, 252 Atk, 252 Spe
Earthquake
Outrage
U-Turn
Stone Edge
There's a reason ScarfGon was pretty dominant in 4th Gen and in UU 5th Gen. He hits fast and hard with great STABs. Flygon works as both a scout and a revenge killer on this team, just like most. This is about your standard Flygon set, pretty much. The only differences might be Fire Punch over Stone Edge or a Jolly nature. I chose Stone Edge over Fire Punch because I don't want to be locked into that in the rain or get screwed over by it, and I chose Adamant over Jolly for the extra power since with a Scarf he'll be outrunning nearly everything anyways. Like Cobalion, I can't say much about him, he's pretty standard and is good at scouting and revenge killing.
As for the title, the peak 13?? thing is because I don't know how high this team has peaked. My account I normally use on PO was banned on the Smogon server, so whenever I wanted some UU laddering I made up some dumb name to get in and play. Usually on the rare times I came in to play UU, after about 30-ish minutes I was one of the top players online at the time (more people really need to play UU) so this team could never get into the 1400s; the highest it's ever gotten was just barely in the 1300s and I don't remember the exact number.
Anyways, like most teams, this team has gone through tons of changing (this final team is the 8th version).
The team-building process...






Version one was mostly a test to try out the idea of a UU rain team. The thought of Swift Swim Kingdra dominating a metagame without permanent weather sounded pretty cool to me, but I didn't know where to begin for compliments. In this version, Machamp was near useless and Kabutops was only useful when their was rain. So if Volbeat died, it felt more like 2 Pokemon died.






Volbeat sucked so I tried a weird Uxie set with Rain Dance/Memento/Stealth Rock/U-Turn. It didn't work out well. Rotom-H was a complete experiment and I replaced Flygon with Cobalion just as an experiment to see how good it is since it appealed to me on paper.






I put Volbeat back and decided to try Weavile and Darmanitan as revenge killers. But even without the rain, Darmanitan didn't do what I wanted him to and Weavile just didn't fit the team at all.






Again I tried experimenting with new compliments for the team. I chose Escavalier since lowering his fire-weakness with rain sounded like a a good idea at the time. Sheer Force Thunders from Nidoking sounded too good to pass up, but he did not perform the way I had hoped.






I tried out Hitmontop as a revenge killer and Snorlax as a wall. Snorlax worked okay enough to survive this version, but Hitmontop didn't.






I decided that I should try out Flygon again as a revenge killer instead of Hitmontop. This team worked out pretty well for awhile, not gonna lie, but it had a few glaring weaknesses (Heracross, anyone?) and I knew I could make it better.






Azumarill worked perfectly as a revenge killer. With rain it was sensational, capable of OHKOing just about anything that had some damage done to it. Without rain, it still hit like a fucking monster and works well as a clean-up Pokemon. While losing Kabutops's Swift Swim put me down a bit, the bulk and sheer power of Azumarill made me wonder why I never used it before. As for Cobalion, I thought this team needed a fighting type and a steel type so voila, Cobalion. I was surprised at how well it worked, the guy was capable of completely shredding unprepared teams and he's a great switch-in and set-up Pokemon.
The team:

Black Widow - Sableye @ Damp Rock
Trait: Prankster
Careful nature (+SpD, -SpA)
EV's: 252 HP, 120 Def, 136 SpD
Rain Dance
Recover
Will-o-Wisp
Confuse Ray
Sableye is a fantastic Pokemon. This set makes it much worse than most since it loses Leftovers for Damp Rock and it loses Foul Play, Taunt, or another move for Rain Dance, but it still works fantastic. Ghost/Dark obviously gives it no weaknesses and the Normal, Fighting, and Psychic immunities are incredibly helpful. All of its priority moves help a lot, making it a good counter to many threats and can let me stall for a few turns if necessary. The only thing she hates are Taunt and Heracross. Taunt makes her completely useless and gives the opponent a turn or two to set up. As for Heracross, he's probably about the biggest threat to this team so it's not too surprising he threatens Sableye. However, Sableye can set up rain and let Azumarill or Kingdra kill Heracross, or I can pray I get lucky and just confuse Heracross hoping it hits itself a turn or two in a row as I switch out.

Captain America - Kingdra @ Life Orb
Trait: Swift Swim
Naughty nature (+Atk, -SpD)
EV's: 252 Atk, 24 SpA, 232 Spe
Dragon Dance
Outrage
Waterfall
Hydro Pump
This guy's pretty much the main sweeper of the team and is one of the main reasons this team is so successful. Honestly, I think the good 'ol Captain has died more often from Life Orb damage than an actual attack. In rain he hits an unrivaled speed stat and the boost to Waterfall and Hydro Pump makes him nigh unstoppable. Dragon Dance is there when either there's no rain around or they switch in something that I can set up on, like a Bronzong. Outrage and Waterfall are the main STABs, but Hydro Pump is there to get rid of physically bulky walls and it has caught many people off-guard. This guy even lets me beat some OU Drizzle teams thanks to permanent Swift Swim.

Hulk - Azumarill @Choice Band
Trait: Huge Power
Adamant nature (+Atk, -SpA)
EV's: 252 HP, 252 Atk, 4 Spe
Aqua Jet
Waterfall
Return
Superpower
You may laugh, but this guy's called Hulk for a good reason. 654 attack is fucking godly and 404 HP is nothing to scoff at. Aqua Jet is almost always the move he'll use, since base 60 priority coming off of 654 attack in the rain spells gg. Waterfall is there when there's something slower like a Snorlax or if I know they're gonna switch. Return is basically only there in case I see a Slowbro or something that resists Water, Fighting, and Ice (I chose Return over Ice Punch). Lastly, Superpower is a pretty fitting move since the team names are based on the Avengers, but it's mostly a last-resort move or to hit something harder than Aqua Jet.

Iron Man - Cobalion @Leftovers
Trait: Justified
Jolly nature (+Spe, -SpA)
EV's: 4 HP, 252 Atk, 252 Spe
Stone Edge
Close Combat
X-Scissor
Swords Dance
He's a steel type so he's close enough to Iron Man, I suppose. This guy's a great counter to the UU dragons as well as Psychics, Darks, and others. There isn't much I can think to say about him. I Swords Dance when I can set-up on something such as an Umbreon or Flygon stuck in Outrage and proceed to sweep from there. 346 speed is pretty good in UU and he's bulkier than many expect with Leftovers so he can keep up a fairly long sweep. He's a bit like a mini-Terrakion (my fave Pokemon in OU) with a better defensive typing. Cobalion and Sableye are pretty much my defensive core. Yeah, I'm just rambling, Cobalion is a good switch-in and can be deadly if he can set up an SDance or two.

Thor - Raikou @Life Orb
Trait: Pressure
Rash nature (+SpA, -SpD)
EV's: 4 HP, 252 SpA, 252 Spe
Aura Sphere
Weather Ball
Thunder
Extrasensory
Ugh, I wish so much that the event Raikou was Timid. Really, the Rash nature is pretty much the main thing that brings him down since his speed takes a pretty big hit, preventing him from being as dominant as he should be. In most of the previous versions of this team, he was the event version and in a few I tried regular Raikou. Aura Sphere and Weather Ball were too sweet of gifts for me to give up for the extra speed. Extrasensory is kind of a filler move, but I don't think replacing it with HP Ice would help too much. But honestly, Thunder, Weather Ball, and Aura Sphere give him great coverage and power. Seriously, Thunder OHKOs or 2HKOs tons of UU Pokemon and Weather Ball is pretty nasty in the rain. Raikou at times can seem like the strongest member of the team and he can sometimes seem like the weakest. I really want to cheat and change his nature to Timid so he'd be fantastic, but I'm too nice of a guy to do that. He's a bit inconsistent depending on the team I face, but he still hits like a nuke and has single-handedly swept many a team.

Hawkeye - Flygon @Choice Scarf
Trait: Levitate
Adamant nature (+Atk, -SpA)
EV's: 4 HP, 252 Atk, 252 Spe
Earthquake
Outrage
U-Turn
Stone Edge
There's a reason ScarfGon was pretty dominant in 4th Gen and in UU 5th Gen. He hits fast and hard with great STABs. Flygon works as both a scout and a revenge killer on this team, just like most. This is about your standard Flygon set, pretty much. The only differences might be Fire Punch over Stone Edge or a Jolly nature. I chose Stone Edge over Fire Punch because I don't want to be locked into that in the rain or get screwed over by it, and I chose Adamant over Jolly for the extra power since with a Scarf he'll be outrunning nearly everything anyways. Like Cobalion, I can't say much about him, he's pretty standard and is good at scouting and revenge killing.