Unown [X] (Darkness, and to Light... No. 065)
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Whenever 1 of your Pokémon with Unown in its name uses its Hidden Power attack, flip a coin until you get tails. That attack does 10 more damage for each heads. If you have more than 1 Unown [X] in play, use only 1 [XXXXX] each turn.

Psychic
Hidden Power
10
Card rule

You may have up to 4 Basic Pokémon cards in your deck with Unown in their names.