An Arma Sword was the weapon of choice of the Arma. The Arma sword was a long/small thin/wide sword made of a special metal that can prevent lightsabers from cutting through it. These swords all contain different abilitites that can be activated by an individual Arma. After Pein "conquered" Spina and its inhabitants, he used his Force Alchemy to create and improve the Arma swords. They could now shapeshift into a different appearence such as a large sword splitting into three thinner swords, a thun sword splitting into four different parts and rotating to form and shiruken-style weapon, or a large sword which grows spikes. The Arma sword could only be used by someone with Arma blood meaning someone not Arma could not use it. Arma sword's abiltites range from sending slashes of visable forc