User blog comment:Maki Kuronami/Weapons Guide (Basics)/@comment-69.146.173.237-20150817223000

And now for my weapon of choice. The weapon of Ferrus Ironclad, the Grimm Knight (He's human, he just is not affiliated with either main group). His weapon, named by his father, is Old Mountain's Bone, a sword of great weight and size made from dust infused metal (a twohanded greatsword), which within the back edge are five quarter sized holes, which allow dust, contained in the right arm of his armor, to flow into the weapon and explode out the holes, resulting in blows far beyond his normal strength. However, he only has so much dust his armor can hold,  and the weapon's weight slows his speed down massively. In addition, he carries no other weapon, leaving him with no alternative method of attack. (For the sake of argument this may or may not spawn, the greatsword and full arm armor are considered one weapon, but only the sword gets jet mode; his armor simply protects and stores him and the dust.)