You may have up to 4 Basic Pokémon cards in your deck with Unown in their names.
Pokémon Power:
[Anger]

Whenever 1 of your Pokémon with Unown in its name uses its Hidden Power attack, that attack does 10 more damage for each damage counter on Unown [A]. If you have more than 1 Unown [A] in play, use only 1 [Anger] for each attack.

Hidden Power 10

• Rarity: Rare Holo
• Type: Psychic
• Number: 14
• Subtype: Basic Pokémon
• Resistance: 0
• Hit Points: 0