Check Mate (Kingdra)
Stats: 252 Attack/252 Speed/4 Hp
Moves: Substitute, Waterfall, Outrage, and Dragon Dance
Nature: Jolly
Item: Leftovers, Life Orb, or Lum Berry
Ability: Swift Swim or Snipper
Kingdra having two powerful attacks in waterfall and outrage gives great coverage in UU, OU, and even in Ubers. Having substitute is great because many walls like rhyperior, claydol and gligar need to switch out fearing waterfall and other attacks. This gives you a great opportunity to sub up and with the sub you can get a free dragon dance and then proceed to outrage or waterfall the rest of the opponent team. As for items you should choose between two items in life orb which gave extra power in its hits, or leftovers is nice because after subbing up you can get instant recovery, and lastly the Lum Berry is useful becuase after outrage it immediately heals its confusion or even if status is inflicted like toxic or thunder wave it can continue to hit hard. Kingdra ability swift swim can be a blessing and a curse it is great in higher tiers like Ubers because it is not banned so it out speeds a lot of uber pokemon, the curse however, is that a drizzle pokemon like politoed is banned in OU and UU. But in my opinion bringing Swift Swim in OU nice because their is a lot weather especially rain so not having to worry about getting in trouble for swift swim drizzle is nice. In UU I would recommend the sniper ability beacuase politoed and other drizzle pokemon are banned so their is less likely chance or having weather a factor in the UU tier.
Counters: Empoleon is a great counter because it resist both of kingdra attacks in waterfall and outrage and can retaliate by phasing it out with roar of ice beam if it is an offensive set. Another great counter is ferroseed or ferrothorn deepening on if it is UU or OU due to ferroseed being grass and steel it resist both waterfall and outrage and can thunder wave it to slow it down or either leach seed to get continuous damage.
Other options for Kingdra can be Rain dance instead of substitute with the addition of the damp rock witch lengthens the amount of turns during the rain is up, but not as good becuase the effects of life orb, leftovers, and lum berry are much more useful than having to deal with a damp rock as your item.