Once during your turn (before your attack), if Blastoise is your Active Pokémon, you may flip a coin. If heads, discard an Energy card attached to Blastoise, if any. Then, if there are any Energy cards attached to the Defending Pokémon, choose 1 of them and discard it. This power can't be used if Blastoise is affected by a Special Condition.
Attacks
40+Energy Cannon
Does 40 damage plus 10 more damage for each Energy attached to Blastoise but not used to pay for this attack's Energy Cost. You can't add more than 20 damage in this way.
How much is Blastoise #4/165 worth?
Blastoise #4/165 is a Rare Holo card from Expedition Base Set (2002) — today it trades at roughly $220.59 ungraded. Across the 2 printings we track, copies run anywhere from $397.50 to $899.99 depending on the version you're holding.
Grading changes the math on this one: a PSA 10 is valued around $13,957.73, roughly 63.3x the raw price, while a PSA 9 sits near $6,460.72. 1,734 copies have been graded to date, and 5% 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.