so...no all 5 stars decks :x but only 1 5 star/deckQuote:
All cards can be classified by rarity (one to five stars). Initially, each deck can only contain one card with a rarity rating higher than one star. As you acquire more cards, however, the restriction becomes less prohibitive, and will eventually only apply to the highest tiers of rarity.
Less than 30 Cards Allowed one card with a rarity of two stars or higher.
Between 30 and 59 Cards No restriction on cards with a rarity of two stars or less. Allowed one card with a rarity of three stars or higher.
60 Cards or More No restriction on cards with a rarity of three stars or less. Allowed one card with a rarity of four stars or higher