I just got this skill over the weekend, and to be honest, I don't think it's really worth it. 5 points and a 5 second cast time? Even if it does increase AP, I was killing mobs a lot faster using Circle Slash II or Onion Cut. The graphics and animation is nice and all, but it really isn't worth losing 2 auto attacks for.

The skill should be reduced to a 3 point skill, or the cast time removed so it fires off just like any other weapon skill.