Magic 15 Volume 3

"Hisuijin."[3]
Acting with the voice, the water in the atmosphere gathered on Yoishigure's edge, and soon took the form of a large Japanese sword. That was a blade of high-pressure circulating water current(s). That was to say, it had the strength of water that wears through stone drip by drip. If it was with a high-pressure current, water could change into a tool that can cut apart even metal like butter.