Dovescape is a rare Enchantment card from RNA Guild Kit (GK2), collector number 11. Current market price: $4.96, TCGplayer market prices via Scryfall.
({W/U} can be paid with either {W} or {U}.) Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value.