It is a chainsaw blade remade into a sword. It is powered by a micro-nuclear core hidden into the the handle and hilt. It is activated when the handle is squeezed.
It can be used much like a regular sword, except is cannot be used for thrusting and stabbing. However its cutting and slashing capacity is far more powerful. It is incredibly useful when used in conjunction with a handgun.
It is based off of Warhammer 40k chain swords.