1. Solaros & Lunaris 
2. manu 11
3. Ransei

2. manu 11

3. Ransei

Doesn't Slaking just do this better?Kabutops as a check.
Kabutops @ Lum Berry
Ability: Swift Swim
EVs: 248 HP / 252 Atk / 252 Def / 252 SpD / 252 Spe
Adamant Nature
- Explosion/Encore
- Swords Dance
- Rock Slide
- Destiny Bond
Kabutops is a check to Kyogre. Thanks to Swift Swim it outspeeds Kyogre and can use either Explosion or Destiny Bond to take it down. Destiny Bond is because Kyogre has Substitute. Rock Slide is just the Stab move and Swords Dance to set up.
The risk of this set is if Kyogre is already behind a sub as you need to potentially predict to Destiny Bond when it is attacking or Rock Slide when it uses Recover/Calm Mind to remove the sub and then use Explosion.
252+ Atk Kabutops Explosion vs. 252 HP / 252 Def Kyogre: 464-547 (114.8 - 135.3%) -- guaranteed OHKO
252+ Atk Kabutops Rock Slide vs. 252 HP / 252 Def Kyogre: 105-124 (25.9 - 30.6%) -- 3.1% chance to 4HKO after Leftovers recovery
You could make this set safer by putting Encore instead of Explosion as to beat Substitute easier and get free set up if they go for Recover/Calm Mind.
The point of using Kabutops is exploiting the rain that Kyogre sets itself with Swift Swim. It allows you to outspeed Kyogre even if it has +1 of Speed and as stated in my post it gives you a set up opportunity. If Kyogre is behind a sub, Slaking has a high chance of just dying (252+ SpA Kyogre Water Spout (150 BP) vs. 252 HP / 252 SpD Slaking in Rain: 461-543 (91.4 - 107.7%) -- 50% chance to OHKO) unlike the Kabutops set that can bring Kyogre down with Destiny Bond. I forgot to mention it in my first post but i also picked Kabutops because it helps vs the best pokemon in the whole meta, Slaking and resist +6 Extreme Speed which is always nice to have.Doesn't Slaking just do this better?
Slaking @ Lum Berry
Ability: No Ability
EVs: 248 HP / 252 Atk / 252 Def / 252 SpD / 252 Spe
Adamant Nature
- Extreme Speed
- Explosion
- Spore
- Haze
The idea is good but sadly gen 3 pure hackmons is kinda weird in that you can't change pokemon's abilities yet (except for pokemon with only 1 ability for which you can have "no ability" which is basically only good for Slaking).![]()
Groudon @ Leftovers
Ability: Water Absorb
EVs: 252 HP / 252 Atk / 252 Def / 252 SpD / 252 Spe
Jolly Nature
- Swords Dance
- Spore
- Earthquake
- Rock Slide
Groudon is a great counter to Kyogre because it doesn't take any damage from Water Spout and can setup SD and kill it with EQ. Jolly nature helps it outspeed so it doesn't have to deal with Substitute shenanigans.
+4 252 Atk Groudon Earthquake vs. 252 HP / 252 Def Kyogre: 461-543 (114.1 - 134.4%) -- guaranteed OHKO
I don't know if the set has to be viable or just has to be able to beat the victim, but if you know please tell me.