Sword of Fighting
From the Dead Gentleman's Wiki:
A mythical sword that appears to be both sentient and homicidal. It can control the arm of its wielder, possibly even the entire body, and is able to make even Perf into an amazing fighter. Despite being intended to bring about a revolution and end the Wicked Kings, the Sword would rather kill things. The Sword is very derisive of Perf, and enjoys tormenting him with the fact that it will follow him everywhere.
Played by Jeremy Spray.