A Practice Sword is used for... Practice

"So why don't you just say, 'I'm the third famous smith' instead of saying that the third famous smith is An Yang."

Tilting his head, An Yang said, "In either case, it gets the information across, and by focusing on abilities and technical details, it's easier to distance oneself from bias."

Letting out a distant nod, Di Tou agreed, "Oh, well, you were saying something about a sword that's not a sword?"

Nodding, An Yang said, "Yes, the third smith who's famous for Life Bound Swords is An Yang, who specializes in swords that aren't swords. In this world, there are many inheritances and paths that don't have well fleshed out inheritances or structures, whereas the sword path is endless, boundless, and well-established. By taking another path as a sword, there's a certain path of seeking enlightenment through a mirror."

His mind in a daze, Di Tou absentmindedly agreed, right, right, enlightenment through a mirror, that made so much sense… NOT.