Once during your turn (before your attack), you may choose 1 of your opponent's Pokémon LV.X. Remove the Level-Up card from that Pokémon and have your opponent shuffle that card into his or her deck. The power can't be used if Gengar is affected by a Special Condition.
Attacks
Compound Pain
This attack does 30 damage to each of your opponent's Pokémon that already has any damage counters on it. (Don't apply Weakness and Resistance for Benched Pokémon.)
How much is Gengar LV.X #97/99 worth?
Gengar LV.X #97/99 is a Rare Holo LV.X card from Arceus (2009) — today it trades at roughly $698.88 ungraded.
Grading changes the math on this one: a PSA 10 is valued around $23,919.23, roughly 34.2x the raw price, while a PSA 9 sits near $7,478.57. 2,421 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.