Kingdra is a powerful rain sweeper that applies immediate offensive pressure to its foes. It outspeeds the entire unboosted metagame when Swift Swim is activated, and its Water-type attacks hit most targets for heavy damage when boosted by rain. Draco Meteor generally allows Kingdra to nuke targets that resist its Water coverage, although strong Fairy-types like Tapu Fini and Tapu Bulu wall Kingdra completely. One of Kingdra's main drawbacks is the middling accuracy of its STAB attacks Muddy Water, Hydro Pump, and Draco Meteor, which are all prone to missing at inopportune moments. It should also be noted that, outside of its STAB moves, Kingdra's offensive coverage is quite underwhelming due to its middling Special Attack stat. Defensively, Kingdra's Water / Dragon typing leaves it with few weaknesses overall, but with a crippling weakness to strong Fairy-types, which are omnipresent in the metagame. Kingdra also faces competition from Ludicolo as a viable Swift Swim sweeper in the metagame. Kingdra boasts higher overall base stats and has access to spread STAB coverage through Muddy Water, but it has a considerably worse matchup against Fairy-types. Kingdra also misses out on Fake Out utility, which Ludicolo is able to provide. Finally, it should be noted that Kingdra relies on its high Speed to maintain a commanding position, and it quickly loses its momentum if the opponent activates an opposing weather or a form of speed control like Tailwind or Trick Room.
name: Rain Attacker
move 1: Muddy Water
move 2: Hydro Pump
move 3: Draco Meteor / Ice Beam
move 4: Protect
item: Waterium Z / Life Orb
ability: Swift Swim
evs: 252 SpA / 4 SpD / 252 Spe
Muddy Water is a powerful spread STAB move that also has a 30% chance to drop the accuracy of each target it hits. Hydro Pump is a single-target STAB attack that can snipe out targets that are just outside of Muddy Water's KO range. It also bypasses Wide Guard Aegislash, a Pokemon that otherwise walls Kingdra. Draco Meteor hits hard against targets that resist Water-type attacks and destroys opposing Dragon-types like Mega Salamence and Zygarde. Beware of Misty Terrain, though, as it halves the power of Draco Meteor against grounded targets. Ice Beam is another option that lets Kingdra snipe out opposing Dragon-types without dropping its Special Attack stat or worrying about Misty Terrain. However, running this leaves Kingdra helpless against bulky Water-types like Milotic, Suicune, and Araquanid. Protect keeps Kingdra safe while its partners deal with any possible threats.
Kingdra's spread isn't complicated. Maximum investments in Special Attack and Speed let it hit as hard and fast as possible under rain. A Modest nature is preferred for maximum power, since the extra Speed granted by a Timid nature isn't generally useful. It is worth noting, however, that a Timid nature on Kingdra is required to outspeed Dragon Dance-boosted Mega Salamence in the rain. Waterium Z grants Kingdra one opportunity to turn Hydro Pump into Hydro Vortex, a move that bypasses Kingdra's otherwise shoddy accuracy and hits all but the bulkiest of targets for heavy damage. Life Orb is an alternative item that can be used for more consistent damage output. Swift Swim doubles Kingdra's Speed when rain is activated.
If the opponent isn't carrying an opposing weather setter, Kingdra and its respective rain setter make for excellent leads that apply immediate offensive pressure, but if they are, consider playing Kingdra more conservatively, opting to take out the opponent's weather setter first if possible. Kingdra quickly becomes dead weight once Swift Swim deactivates, so it is best saved for a point in the match where rain can't be disrupted. If you're able to clear out Kingdra's checks and counters beforehand, it also makes for an excellent late-game cleaner, outspeeding and picking off weakened foes with strong spread damage. When in play, Kingdra's main goal is to spam Muddy Water and consistently chip away at the opponent's team. Hydro Pump can also be used to snipe down targets that are just outside of Muddy Water's KO range. Use Draco Meteor with caution, as Kingdra quickly loses momentum once its Special Attack drops to -2. Also keep in mind that Misty Terrain halves Draco Meteor's power against grounded targets like Zygarde. If using Waterium Z, be mindful that Hydro Vortex is a one-time nuke; avoid using it on a turn where the opponent is likely to Protect or switch into a Water-resistant Pokemon. Finally, Kingdra's bulk is average at best, and Life Orb sets in particular are prone to getting worn down quickly, so avoid pivoting Kingdra in on opposing attacks if you can.
Kingdra is a dedicated rain attacker, so it goes without saying that running either Politoed or Pelipper as a rain setter is mandatory. Politoed offers higher overall bulk and has access to Helping Hand, which further amplifies Kingdra's attacks. Pelipper has access to Tailwind, a second form of speed control that reduces Kingdra's dependency on Swift Swim being activated. On hyper offensive teams, Kingdra pairs notably well with Tapu Lele and Psychic Terrain attackers such as Deoxys-A and Mega Metagross. Psychic Terrain blocking priority attacks reinforces Kingdra's commanding Speed tier inside of rain. Deoxys-A and Mega Metagross apply immense offensive pressure to targets that resist Kingdra's STAB moves, such as Tapu Fini and Milotic. Likewise, these Psychic-types appreciate Kingdra's ability to clear out bulky Steel-types such as Heatran and Aegislash. On more balance-oriented teams, bulky Steel-types such as Celesteela and Aegislash make for excellent partners, as they can pivot in on the strong Fairy- and Dragon-type attacks that Kingdra hates. In general, rain teams with Kingdra generally don't have the luxury of running Fire-type attackers, so they are especially vulnerable to being walled by late-game stall wincons such as Celesteela and Ferrothorn. Therefore, it is strongly recommended that Kingdra be partnered with Pokemon that have access to strong Electric and Fighting-type coverage. They also come in handy for beating Mega Charizard and Tyranitar, respectively. Tapu Koko, Zapdos, and Thunder Punch Mega Metagross are all great options for beating Celesteela, and as an added bonus, they also threaten Tapu Fini, which is a prominent check to rain teams. Landorus and Terrakion are decent options for dealing with Ferrothorn, although admittedly Ferrothorn will almost always be a problem for rain teams. Kingdra relies on Swift Swim to maintain a commanding position, so partners that can deal with opposing weather setters and speed control techniques are always a good idea. Running Taunt on at least one partner helps to shut down opposing Tailwind and Trick Room users. Opposing speed control can also be countered with your own, so consider running Tailwind users like Zapdos and Pelipper or Icy Wind users such as Politoed.
Dragonium Z is an alternative item that allows Kingdra to snipe a target with Draco Meteor without suffering a Special Attack drop. Scald can be used over Hydro Pump for more reliable accuracy at the expense of less power. However, doing so is contrary to Kingdra's main goal of hitting as hard and fast as possible. Mystic Water is usable over Life Orb to boost Kingdra's Water-type attacks without wearing it down. Rain Dance is an option that allows Kingdra to maintain its rain advantage, especially against opponents planning to switch in an opposing weather setter. If you're not concerned about losing against a Kingdra mirror, you can drop Kingdra's Speed EVs down to 192 and invest the rest into HP; this gives it slightly more bulk, allows it to outspeed Modest Heatran outside of rain, and allows it to still outspeed the entire unboosted metagame under rain.
Checks and Counters
**Fairy-types**: Bulky Fairy-types like Tapu Fini and Tapu Bulu completely wall Kingdra's STAB coverage and threaten back with STAB-boosted Moonblasts or Grassy Terrain-boosted Wood Hammers. Tapu Lele and Tapu Koko also threaten Kingdra with strong Fairy- and Electric-type attacks, respectively, but inside of rain, Kingdra can threaten to outspeed and KO them first with strong Water-type attacks.
**Grass-types**: Bulky Grass-types such as Tapu Bulu and Amoonguss are capable of absorbing Kingdra's STAB coverage and hitting back either with strong Grass-type moves or with status moves such as Spore.
**Water-types**: Bulky Water-types such as Tapu Fini, Milotic, and Araquanid have enough bulk and the right typing to absorb Kingdra's STAB attacks. Tapu Fini can then hit back with a STAB-boosted Moonblast, while Milotic can simply use Recover to negate the damage. Milotic also gains a sharp Special Attack boost if its accuracy is lowered by Muddy Water. Araquanid can block Kingdra's Muddy Water with Wide Guard for as long as it stays on the field.
**Opposing Weather**: Kingdra quickly becomes dead weight outside of rain, since it relies on its Swift Swim Speed boost to maintain its offensive pressure. Therefore, opposing weather setters like Mega Charizard Y, Tyranitar, and Alolan Ninetales can be problematic for Kingdra.
**Tailwind and Trick Room**: Tailwind and Trick Room either negate or reverse Kingdra's Swift Swim Speed boost. Prominent Trick Room setters such as Hoopa-U and Bronzong are also generally bulky enough to survive one attack from Kingdra, although a well-timed Hydro Vortex inside of rain is generally able to OHKO them before they set Trick Room. A Zapdos carrying Misty Seed or Psychic Seed is a particularly thorny Tailwind setter for Kingdra to deal with, as it has enough bulk to withstand all of Kingdra's attacks outside of Hydro Vortex. However, Zapdos almost never carries Protect, so Kingdra is pretty safe to use up its Hydro Vortex on an opposing Zapdos.