This is the Tuten-Ku insignia. Only the high ranking Mystics will adorn it. Tuten-Ku, as you know it, is a hidden power inside all fighters around the world. Every clan leader that wears the symbol bears the responsibility of protecting their library of knowledge, fighting systems, protecting the people, winning tournaments, honoring power, and keeping the principles of fists. Long ago, it is said that when a Mystic is slayed in battle their book(s) would transcend to Hyetheren to prevent the knowledge from falling into the wrong hands.