Cada oponente exilia cartas de la parte superior de su biblioteca hasta que haya exiliado cartas con un valor de maná total de 5 o más de esta manera. Hasta el final del turno, puedes lanzar las cartas exiliadas de esta manera sin pagar sus costes de maná.
If a spell you cast has
in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
Since you are using an alternative cost to cast the spells, you can't pay any other alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, you must pay those.
If a card in a library has
in its mana cost, X is 0 for the purpose of determining its mana value.