The term "supernatural martial arts" refers to the origin of the maneuvers, rather than them being magical.  It also covers the fact that in my version of the setting, the list of maneuvers is fixed and cannot be expanded.<br/><br/>Hound Archons aren't strictly magical either, but they are supernatural in origin, as opposed to say, wolves.  The difference between a nine swords style and conventional feats is about the same as the difference between a hound archon and a dog.<br/><br/>Much like a cleric developing divine spellcasting through the power of faith, an individual could learn maneuvers without a tutor, although it requires a degree of philisophical harmony with the school of maneuvers being practiced.  The maneuvers developed however, would come from exactly the same set as ay other individual who studied the same school.