I'm not sure about that. The description reads:<br/><br/>"Benefit: Characters can use a katana two-handed as a martial weapon, but must take the Exotic Weapon Proficiency (katana) feat to use it one-handed."<br/><br/>I know that it can be used as a martial weapon, but if I still have to take a feat, it's a waste of the stone. I could try ancestrial weapon as a half elf, which gives proficiency, but does that actually count as a feat? I'm reluctant to go that route because it's a normal weapon with no potentiental to improve without a 2nd level bard spell that no one is likely to have.