Magic 17 Volume 4

Declaring this, Shizuku waved Yoishigure like a conductor's baton from within her sphere of water. In accord with her movement, the mass of water wrapped around her took the form of enormous lashes. From the tips of the many lashes, the gathered water froze.
They took the shape of a thorn-covered hammer, and the hammer of ice swung down upon Wallenstein. The hammer of ice struck violently without mercy, breaking the training arena floor with a cloud of dust and a thunderous roar