Drill Sword

The Drill Sword is a technique used by Jean (and later, Helen), wherein the Claymore twists her arm a number of times, then releases it, creating a drill effect. Jean first uses this technique to defeat Dauf. She is shown to be able to twist her arm up to 21 times, using up almost 50% of her yoki. Helen, however, managed to reproduce this technique without expending any yoki at all.