Maralen, Fae Ascendant

Legendary Creature — Elf Faerie Noble — {2}{B}{G}{U}

Flying Whenever Maralen or another Elf or Faerie you control enters, exile the top two cards of target opponent's library. Once each turn, you may cast a spell with mana value less than or equal to the number of Elves and Faeries you control from among cards exiled with Maralen this turn without paying its mana cost.