Head-to-head
Groudon vs Kyogre
The Gen 3 weather war — Ground vs Water, Drought vs Drizzle.
Side-by-side
Groudon
Ground/None · #0383
BST: 670
Kyogre
Water/None · #0382
BST: 670
Verdict
Winner: Primal Groudon
in base-form, Kyogre wins. In Primal forms, Groudon wins the mirror due to Desolate Land blocking Water moves entirely.
Context: why this matchup matters
Groudon and Kyogre are the two cover legendaries of Ruby and Sapphire (Gen 3, 2002). They're the textbook 'opposing forces' in Pokémon design: Groudon controls land and sun; Kyogre controls sea and rain. Both have 670 BST. Both summon permanent weather via their signature abilities (Drought / Drizzle in their base forms; Desolate Land / Primordial Sea via their Primal forms in ORAS). They've defined Ubers and VGC restricted formats for 20+ years.
Stat battle: who has the numbers?
Groudon: 100/150/140/100/90/90 BST 670. Physical attacker (150 Atk) with insane Defense (140). Kyogre: 100/100/90/150/140/90 BST 670. Special attacker (150 SpA) with high SpDef (140). Mirror-image stat distributions. Speed is tied at 90 — both are slow, neither outspeeds the other consistently. Primal forms add 100 BST each: Primal Groudon (770 BST: 100/180/160/150/90/90 — gains 30 SpA), Primal Kyogre (770 BST: 100/150/90/180/160/90 — gains 50 Atk, 30 SpDef).
Full matchup analysis
1-on-1 matchup: In their base forms, Kyogre wins in rain (which it auto-sets). Origin Pulse (Kyogre's signature Water STAB) hits Groudon for 4× damage (Ground 2× Water + Sun doesn't help Groudon's typing). Groudon's only way to win is to switch in first and set Sun, then Solar Beam — but Origin Pulse one-shots even bulky Groudon.
In Primal forms: the calculus changes. Primal Groudon's Desolate Land completely nullifies Water moves — Kyogre cannot use Water-type attacks at all. Primal Groudon then OHKOes Primal Kyogre with Precipice Blades (Ground STAB hits Water for 2×, supercharged by Sun). Primal Groudon wins the Primal mirror.
Critical caveat: the form that switches in LAST controls weather. If Kyogre switches in after Groudon, Primordial Sea overwrites Desolate Land, and Kyogre wins. Speed ties (90 base each) means coin-flip on who switches first.
When to pick each
Pick Groudon for: Sun teams, physical-attacker cores, Drought support for Charizard / Venusaur Chlorophyll sweepers, and Trick Room builds. Primal Groudon is the best physical attacker in the franchise's history.
Pick Kyogre for: Rain teams, special-attacker cores, Drizzle support for Kingdra / Iron Bundle / Barraskewda Swift Swim sweepers, and Hydro Pump nuke specialists. Primal Kyogre's Origin Pulse + Thunder coverage handles most Ubers threats.