For your first set why not replace hidden power poison for flash cannon? That also hits fairy types for super effective damage and has a higher base power than hidden power and also has the chance to lower special defense.
Kingdra, the feared Pokemon of Clair & Juan
Kingdra is quite the popular and memorable Pokemon due to how tough it's defenses and offenses are late in the game that I'm actually surprised that Kingdra hasn't had any major appearances in the anime since Clair from Gen 2, like literally not even Gen 5 where Clair makes a reappearance and Gen 3 where Kingdra is the signature Pokemon of Juan. Really weird but outside of Clair & Juan, there's another Kingdra user that Pokemon Adventure fans know about and that's none other than Silver who you may know from the games as Gen 2's rival character. What's interesting about Silver's Kingdra is that it was originally a Horsea given to him by a very close friend and has since then grown up to become one of Silver's most powerful Pokemon.
Well-Known Trainers who caught or befriended the Kingdra evolution line.
Kingdra - Clair (Games, Adventures manga, Anime)
Kingdra - Juan (Games, Adventures manga)
Seadra - Lance (Games)
Kingdra - Silver (Adventures manga)
Horsea (Given) - Green/Blue (Fem Protag, Adventures Manga)
Horsea - Misty (Anime)
Kingdra (Imaginary) - Molly (Movie)
Seadra - Fergus (Movie)
Seadra - Cissy (Anime)
Swift Swim Kingdra
Item: Leftovers/Damp Rock/Assault Vest
Ability: Swift Swim
Nature: Modest Nature (+ Sp. Atk, - Atk)
EVs: 252 Sp. Atk/252 HP
Rain Dance/Hidden Power Poison (Assault Vest)/Hidden Power Grass (Assault Vest)
Draco Meteor/Dragon Pulse
Kingdra is quite the monster on rain-dance teams. Even with the introducing of fairy-types and the much better bulkier hard hitting Mega Swampert, Kingdra's water-dragon typing bulk with decent offenses and the ability Swift Swim is still something to be feared. In fact, with no investment in it's speed with a non-speed nature, Kingdra can still outspeed almost every non-legendary unboosted Pokemon under Rain Dance that some players might think it's better to invest it in Kingdra's bulk and even further with Assault Vest if you have another Pokemon that activated Rain Dance.
Juan's Dragon Dance Kingdra
Ability: Swift Swim or Sniper
Nature: Adamant Nature (+ Atk, - Sp. Atk)
EVs: 252 Atk/252 HP or 252 Atk/252 Spe
Juan is acknowledged by many fans as Wallace's mentor and is the reason why Wallace uses so many stylish battle tactics as the "Contest Master", a title first introduced in Pokemon Adventures long before it was adapted as main series canon in ORAS. So even though it never happened in the games, it makes a lot of sense that a "Stylish" Kingdra under Juan has dragon dance don't you think? For this set, Dragon Dance is key to making Adamant Kingdra work and one could risk using it twice for extra bulk investment but one is enough for those who want to play it save with speed investment.
Laser Focus is arguably a better option than Focus Energy. Since Laser Focus guarantees a critical hit, you can forgo the Scope Lens for a different item.Kingdra @ Scope Lens
EVs: 4 HP, 252 Sp.Atk, 252 Speed
- Focus Energy
- Draco Meteor
- Hydro Pump
Critical hit Kingdra. With Focus Energy and a Scope Lens, Kingdra will always score a critical hit, which will do a lot of damage with Sniper. Spam Draco Meteor. It tanks your Sp.Atk, but because critical hits ignore drops in offensive stats it doesn't matter. Agility is there to boost your speed as you are somewhat frail, although it's hard to set up both Focus Energy and Agility. Hydro Pump is the other STAB move. This Kingdra can hit very hard. Critical hit Draco Meteor OHKOs a lot of things that do not resist it, even bulkier targets like Mega Kangaskhan go down in a single hit. Ideally you do get passed some kind of speed boost, something like Blaziken can Baton Pass speed quite well.
Laser Focus only guarantees crits for moves during your next turn, after that it wears off. Focus Energy stays until switched out.Laser Focus is arguably a better option than Focus Energy. Since Laser Focus guarantees a critical hit, you can forgo the Scope Lens for a different item.