Ariel, Priestess of the Nekroz

“Once per turn: You can reveal any number of "Nekroz" cards in your hand; increase or reduce this card's Level by the number of revealed cards until the end of this turn. If this card is Tributed by a card effect: You can add 1 "Nekroz" monster from your Deck to your hand, except a Ritual Monster. You can only use this effect of "Ariel, Priestess of the Nekroz" once per turn.”