I figured since Kingdra is falling off of OU for good now, I'd open the floor to discuss his uber potential. Pun intended... I use Kingdra extensively in ubers as my premier sweeper, accompanied by Kyogre as one of the deadliest duos in the game. With infinite rain, and an area there is a limited number of bulky water and grass types, Kingdra thrives and fills quite the niche.
Meet... Uber Kingdra!
[SET]
name: Uber Kingdra
move 1: Surf
move 2: Draco Meteor
move 3: Dragon Pulse
move 4: Waterfall
item: Life Orb
ability: Swift Swim
nature: Mild
evs: 192 At / 64 Spd / 252 SpA
[SET COMMENTS]
<p> Typical Kingdra set without rain dance, as it is meant to be used in tandem with Kyogre. Between Scarf Kyogre and Kingdra, you should decimate the uber metagame. Since I'm promoting this set, here are the obligatory Damage Calcs against most things you will find in ubers... All the calcs were done by the smogon AMF Calculator http://pokedex-br.info/damage.html and percents done by hand.<p>
Kingdra's Waterfall against Blissey (4HP/252Def, Calm)
58.99-69.59% - Easy 2HKO
Kingdra's Surf against Darkrai(0HP/SpD)
103.56-122.78% - Easy OHKO
Kingdra's Waterfall against same Darkrai
75.09-88.97%
Kingdra's Surf against Deoxys-A(4HP/0SpD)
343.57-404.56% - Ouch
Kingdra's Waterfall against same Deoxys
250.21-295.02%
Kingdra's Surf against Deoxys-D(252HP/176SpD, Calm)
47.37-55.59% - Always 2HKO with SR
Kingdra's Surf against Mixalga (120HP/0SpD)
35.85-42.32%
Kingdra's Draco Meteor against Mixalga (120HP/0SpD)
70.62-83.29%
Kingdra's Surf against Forretress (252HP/160SpD, Relaxed)
110.17-129.66% - Easy OHKO
Kingdra's Dragon Pulse against Garchomp (4HP/0SpD)
109.55-128.65% - Easy OHKO
Kingdra's Draco Meteor against Giritina (252HP/12SpD, Impish)
88.10-103.97% -Always OHKO with SR
Kingdra's Dragon Pulse against same Giritina
57.14-67.00%
Kingdra's Surf against ScarfHeracross (4HP/0SpD)
91.72-108.28% - Likely OHKO, always with SR
Kingdra's Waterfall against same Heracross
81.15-95.70%
Kingdra's Waterfall against Ho-oh(248HP/252SpD, Calm)
101.44-120.19% - Solid OHKO
Kingdra's Surf against ScarfKyogre (4HP/0SpD)
29.33-34.60%
Kingdra's Draco Meteor against ScarfKyogre (4HP/0SpD)
57.18-67.74%
Kingdra's Draco Meteor against TankKyogre (252HP/0SpD)
48.21-57.18%
Kingdra's Draco Meteor against bulky Soul Dew Latias (128HP/0SpD)
76.28-90.00% -Chance at OHKO with SR
Kingdra's Dragon Pulse to same Latias
50.45-59.46%
Kingdra's Draco Meteor against Soul Dew Latios (4HP/0SpD)
98.01-115.89% - Easy OHKO
Kingdra's Dragon Pulse against same Latios
62.25-74.17%
Kingdra's Surf against Lugia (252HP/0SpD)
44.00-51.92% - 2HKO with SR
Kingdra's Draco Meteor against Manaphy (80HP/0SpD)
72.58-85.60% - get some spikes and OHKO
Kingdra's Surf against Metagross (232HP/0SpD)
82.95-98.01% - Solid chance at OHKO
Kingdra's Surf against Mew (252HP/0SpD)
66.09-77.97% - Solid 2HKO
Kingdra's Surf against Mewtwo (4HP/0SpD, neutral)
82.49-97.48% - Likely OHKO, extra layer of spikes will get him
Kingdra's Waterfall against same Mewtwo 59.60-70.6%
Kingdra's Dragon Pulse against Palkia (0HP/0SpD)
89.72-106.54% - Solid OHKO
Kingdra's Surf against Skarmory (252HP/0SpD)
106.88-125.75% - Easy OHKO
Kingdra's Waterfall against Tyranitar (60HP/0Def) in Sandstorm
66.29-79.2% - Weaken him
<p>So there you have it, the damage calcs. These are all the pokemon you will likely find in ubers that are WORTH LEAVING KINGDRA IN ON. I will mention specifics in the counter section. Kingdra is best used in tandem with Lugia for defensive support, and a few layers of spikes or stealth rock. Learn the calcs. Kingdra only gets 11 turns of mayhem, and knowing what can be picked off is most effective. Some of the weaker pokemon have Waterfall, as if you use Draco Meteor, you may be able to pick them off with a waterfall before switching out. Don't use Draco Meteor unless it is needed, otherwise, you cant complete the sweep. So basically, weaken what needs to be weakened and watch this thing clean ubers like its his day job.
<p>Take a look, tank Kyogre is the only thing that can switch in without dying the subsequent turn one way or another. If Scarfogre and Mixalga switch in on a surf, Draco Meteor will finish them the next turn ALWAYS, provided Stealth Rock is in play. If you don't recognize the power of the best "BL" pokemon in the game, try it out!<p>
[EVs]
The EVs listed are sufficient for Kingdra to perform his task. His special attack is maxed for max output damage, and Life Orb really gives him the crucial kick to be deadly in ubers. 64 Speed EVs grants Kingdra 222 Speed, enough to outpace Tyranitar in a Sandstorm, and Max positive nature Deoxys-A in rain. If you feel the pressure from Scarf Palkias, just reallocate the EVs as needed, taking from physical attack. You will have to take quite a bit out to lose the 2HKO on Blissey, so don't be stingy because you don't want to lose him to another dragon!
[Counters]
<p> Kingdra hates status, so a Blissey in ubers packing Thunderwave will spell its demise. Be weary of Thunders, as they can really render him useless with a timely paralysis.
<p> Raquaza will make Kingdra run for its life as it will negate Swift Swim and Outrage Kingdra into the next dimension. Stay away at all costs! Tyranitar can also negate swift swim, but really can't stay in, as waterfall will KO the next turn. Groudon is also a HUGE problem, as it will dry up Kingdra's rampage and can send it flying with a powerful attack.
<p> Arceus cannot switch in, but can eat a Surf, SD up and Extremespeed Kingdra to its death. Bulk-up Dialga with a large Sp Def investment can also eat Kingdra's attacks and send it home with Dragon Claw. As residual Life Orb damage adds up, Deoxys-A can finish it with Extremespeed.<p>
Meet... Uber Kingdra!

[SET]
name: Uber Kingdra
move 1: Surf
move 2: Draco Meteor
move 3: Dragon Pulse
move 4: Waterfall
item: Life Orb
ability: Swift Swim
nature: Mild
evs: 192 At / 64 Spd / 252 SpA
[SET COMMENTS]
<p> Typical Kingdra set without rain dance, as it is meant to be used in tandem with Kyogre. Between Scarf Kyogre and Kingdra, you should decimate the uber metagame. Since I'm promoting this set, here are the obligatory Damage Calcs against most things you will find in ubers... All the calcs were done by the smogon AMF Calculator http://pokedex-br.info/damage.html and percents done by hand.<p>
Kingdra's Waterfall against Blissey (4HP/252Def, Calm)
58.99-69.59% - Easy 2HKO
Kingdra's Surf against Darkrai(0HP/SpD)
103.56-122.78% - Easy OHKO
Kingdra's Waterfall against same Darkrai
75.09-88.97%
Kingdra's Surf against Deoxys-A(4HP/0SpD)
343.57-404.56% - Ouch
Kingdra's Waterfall against same Deoxys
250.21-295.02%
Kingdra's Surf against Deoxys-D(252HP/176SpD, Calm)
47.37-55.59% - Always 2HKO with SR
Kingdra's Surf against Mixalga (120HP/0SpD)
35.85-42.32%
Kingdra's Draco Meteor against Mixalga (120HP/0SpD)
70.62-83.29%
Kingdra's Surf against Forretress (252HP/160SpD, Relaxed)
110.17-129.66% - Easy OHKO
Kingdra's Dragon Pulse against Garchomp (4HP/0SpD)
109.55-128.65% - Easy OHKO
Kingdra's Draco Meteor against Giritina (252HP/12SpD, Impish)
88.10-103.97% -Always OHKO with SR
Kingdra's Dragon Pulse against same Giritina
57.14-67.00%
Kingdra's Surf against ScarfHeracross (4HP/0SpD)
91.72-108.28% - Likely OHKO, always with SR
Kingdra's Waterfall against same Heracross
81.15-95.70%
Kingdra's Waterfall against Ho-oh(248HP/252SpD, Calm)
101.44-120.19% - Solid OHKO
Kingdra's Surf against ScarfKyogre (4HP/0SpD)
29.33-34.60%
Kingdra's Draco Meteor against ScarfKyogre (4HP/0SpD)
57.18-67.74%
Kingdra's Draco Meteor against TankKyogre (252HP/0SpD)
48.21-57.18%
Kingdra's Draco Meteor against bulky Soul Dew Latias (128HP/0SpD)
76.28-90.00% -Chance at OHKO with SR
Kingdra's Dragon Pulse to same Latias
50.45-59.46%
Kingdra's Draco Meteor against Soul Dew Latios (4HP/0SpD)
98.01-115.89% - Easy OHKO
Kingdra's Dragon Pulse against same Latios
62.25-74.17%
Kingdra's Surf against Lugia (252HP/0SpD)
44.00-51.92% - 2HKO with SR
Kingdra's Draco Meteor against Manaphy (80HP/0SpD)
72.58-85.60% - get some spikes and OHKO
Kingdra's Surf against Metagross (232HP/0SpD)
82.95-98.01% - Solid chance at OHKO
Kingdra's Surf against Mew (252HP/0SpD)
66.09-77.97% - Solid 2HKO
Kingdra's Surf against Mewtwo (4HP/0SpD, neutral)
82.49-97.48% - Likely OHKO, extra layer of spikes will get him
Kingdra's Waterfall against same Mewtwo 59.60-70.6%
Kingdra's Dragon Pulse against Palkia (0HP/0SpD)
89.72-106.54% - Solid OHKO
Kingdra's Surf against Skarmory (252HP/0SpD)
106.88-125.75% - Easy OHKO
Kingdra's Waterfall against Tyranitar (60HP/0Def) in Sandstorm
66.29-79.2% - Weaken him
<p>So there you have it, the damage calcs. These are all the pokemon you will likely find in ubers that are WORTH LEAVING KINGDRA IN ON. I will mention specifics in the counter section. Kingdra is best used in tandem with Lugia for defensive support, and a few layers of spikes or stealth rock. Learn the calcs. Kingdra only gets 11 turns of mayhem, and knowing what can be picked off is most effective. Some of the weaker pokemon have Waterfall, as if you use Draco Meteor, you may be able to pick them off with a waterfall before switching out. Don't use Draco Meteor unless it is needed, otherwise, you cant complete the sweep. So basically, weaken what needs to be weakened and watch this thing clean ubers like its his day job.
<p>Take a look, tank Kyogre is the only thing that can switch in without dying the subsequent turn one way or another. If Scarfogre and Mixalga switch in on a surf, Draco Meteor will finish them the next turn ALWAYS, provided Stealth Rock is in play. If you don't recognize the power of the best "BL" pokemon in the game, try it out!<p>
[EVs]
The EVs listed are sufficient for Kingdra to perform his task. His special attack is maxed for max output damage, and Life Orb really gives him the crucial kick to be deadly in ubers. 64 Speed EVs grants Kingdra 222 Speed, enough to outpace Tyranitar in a Sandstorm, and Max positive nature Deoxys-A in rain. If you feel the pressure from Scarf Palkias, just reallocate the EVs as needed, taking from physical attack. You will have to take quite a bit out to lose the 2HKO on Blissey, so don't be stingy because you don't want to lose him to another dragon!
[Counters]
<p> Kingdra hates status, so a Blissey in ubers packing Thunderwave will spell its demise. Be weary of Thunders, as they can really render him useless with a timely paralysis.
<p> Raquaza will make Kingdra run for its life as it will negate Swift Swim and Outrage Kingdra into the next dimension. Stay away at all costs! Tyranitar can also negate swift swim, but really can't stay in, as waterfall will KO the next turn. Groudon is also a HUGE problem, as it will dry up Kingdra's rampage and can send it flying with a powerful attack.
<p> Arceus cannot switch in, but can eat a Surf, SD up and Extremespeed Kingdra to its death. Bulk-up Dialga with a large Sp Def investment can also eat Kingdra's attacks and send it home with Dragon Claw. As residual Life Orb damage adds up, Deoxys-A can finish it with Extremespeed.<p>