#0383 · Gen 3 · Legendary

Groudon (Primal) — Best counters

Weaknesses

water×2.56 double weaknessground×1.60

	Pokémon	Fast move	Charged move	Weather	Score
1	Kyogre (Primal)	waterWaterfall	waterOrigin PulseELITE	Rainy	10020.7
2	Swampert (Mega)	waterWater Gun	waterHydro CannonELITE	Rainy	8417.4
3	Blastoise (Mega)	waterWater Gun	waterHydro CannonELITE	Rainy	7816.2
4	Gyarados (Mega)	waterWaterfall	waterHydro Pump	Rainy	7716.0
5	Sharpedo (Mega)	waterWaterfall	waterHydro Pump	Rainy	7615.8
6	Kyogre	waterWaterfall	waterOrigin PulseELITE	Rainy	7615.8
7	Quaquaval	waterWater Gun	waterHydro CannonELITE	Rainy	7014.5
8	Greninja	waterWater Shuriken	waterHydro CannonELITE	Rainy	6914.4
9	Kingler	waterBubble	waterCrabhammer	Rainy	6914.2
10	Primarina	waterWaterfall	waterHydro CannonELITE	Rainy	6713.8
11	Inteleon	waterWater Gun	waterSurf	Rainy	6613.6
12	Volcanion	waterWater Gun	waterHydro Pump	Rainy	6513.5
13	Sharpedo	waterWaterfall	waterHydro Pump	Rainy	6413.3
14	Clawitzer	waterWater Gun	waterCrabhammer	Rainy	6313.1
15	Crawdaunt	waterWaterfall	waterCrabhammer	Rainy	6313.0
16	Gyarados	waterWaterfall	waterHydro Pump	Rainy	6313.0
17	Swampert	waterWater Gun	waterHydro CannonELITE	Rainy	6212.8
18	Groudon (Primal)	groundMud Shot	groundPrecipice BladesELITE	Clear	6212.7
19	Samurott	waterWaterfall	waterHydro CannonELITE	Rainy	6112.6
20	Feraligatr	waterWater GunELITE	waterHydro CannonELITE	Rainy	6112.6

Water hits for ×2.56 — Groudon (Primal)'s Ground/Fire typing is double-weak, so those attackers outperform their score gap.
Watch its Ground/Dragon/Fire/Grass moves — counters like Kyogre (Primal) and Swampert (Mega) take super-effective damage from them.
Rainy weather boosts Water moves ×1.2 — the best time to battle Groudon (Primal).

Rankings are estimated cycle DPS (attack stat × move damage ÷ cycle time, with STAB and type effectiveness). Not a full battle simulation.