Giriko

Giriko is a Demon Weapon and an ally to the witch Arachne. He lives for fighting, and likes to be destructive. Giriko takes the form of a chain saw in weapon form. Although he is a weapon like Tsubaki or Soul, he openly states his hatred for Shibusen, claiming that he wants to follow his own path will rather than be used by a meister. Hence, he fights solo, using martial techniques while chains circle around his body. He also uses his chains as a form of transportation, like caterpillar treads on a tank. Giriko is not very good at remembering faces, as seen when he does not recognize Maka when she infiltrates into Arachne's castle with the other Shibusen students. He has formed a rivalry with death scythe Justin Law, as they both are weapons who fight without meisters.

(Source: Wikipedia)