The Water Crystal

In the rare case where you control two of The Water Crystal, each opponent mills eight more cards than originally instructed. If you control three, your opponents mill twelve more, and so on.

To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Water Crystal's first ability). The mana value of the spell is determined by only its mana cost, no matter what the total cost to cast that spell was.

The cost reduction applies only to generic mana in the total cost of blue spells you cast.