Goyakan

"The Macuahuitl (Maquahuitl) was a wooden sword-like weapon used primarily by the Aztecs. It was generally 3-4 feet in length and had grooves along its edges lined with sharpened pieces of obsidian. It was noted by Spanish settlers to be a very well-constructed weapon, with the obsidian almost impossible to pull free from the wood, and strong and sharp enough to decapitate a man."

This weapon was created with Senju wood and obsidian by Sabumaru in Baijing, and is made to be indestructable.