Once during your turn (before your attack), you may search your deck for another Unown and switch it with Unown. (Any cards attached to Unown, damage counters, Special Conditions, and effects on it are now on the new Pokémon.) If you do, put Unown on top of your deck. Shuffle your deck afterward. You can't use more than 1 Shuffle Poké-Power each turn.
Attacks
Hidden Power
Flip a coin. If heads, switch all damage counters on Unown with those on the Defending Pokémon. (If an effect of this attack is prevented, this attack does nothing.)
How much is Unown #J/115 worth?
Unown #J/115 is a Rare card from Unseen Forces (2005) — today it trades at roughly $33.75 ungraded. Across the 2 printings we track, copies run anywhere from $29.99 to $1,809.68 depending on the version you're holding.
Grading changes the math on this one: a PSA 10 is valued around $607.48, roughly 18.0x the raw price, while a PSA 9 sits near $190.42.
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.