As long as your opponent has Groudon, Groudon ex, Rayquaza, or Rayquaza ex in play. Kyogre ex's attacks do 40 more damage to the Defending Pokémon (before applying Weakness and Resistance).
Attacks
30Aqua Supply
You may attach a basic Energy card from your hand to 1 of your Pokémon.
40Tsunami
Does 10 damage to each of your opponent's Benched Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)
How much is Kyogre ex #37/40 worth?
A raw copy of Kyogre ex #37/40 (Nintendo Black Star Promos, 2003) is worth about $116.41 right now, based on the latest market data from November 6, 2026.
Grading changes the math on this one: a PSA 10 is valued around $55,000.00, roughly 472.5x the raw price, while a PSA 9 sits near $3,721.88. 1,207 copies have been graded to date, and 2% of them came back a 10 — worth knowing before you pay grading fees.
These figures come from nightly market-data syncs verified against completed sales. Use the chart above to see the trend before you buy or sell.