Ariel, Prêtresse des Nékroz MP18-FR007

Once per turn, you can reveal any number of "Nekroz" cards from your hand. Until the end of this turn, increase or decrease the Level of that card by the number of revealed cards. If that card is Tributed by a card effect, you can add 1 "Nekroz" monster (except Ritual Monsters) from your Deck to your hand. You can only use this effect of "Ariel, Priestess of the Nekroz" once per turn.