The chainsaw is a powerful close range weapon. It allows the player to trigger a unique glory kill on a demon (provided that they have enough fuel). Small demons like the Possessed or Imps only require 1 fuel to kill, larger demons like Revenants or Pinkies need 3 fuel and finally Barons of Hell and Mancubi need 5 fuel. Demons killed by the chainsaw will drop large amounts of ammo, almost immediately refilling all ammo. Due to this, it is recommended to use the Chainsaw when player is low on ammo.
The chainsaw starts out with a capacity of three fuel, but can be upgraded when the player uses an Argent Energy Cell to upgrade his ammo capacity, with each cell upgrading the capacity by one.
It is unknown if the chainsaw is made with strengthened material, as it is capable of easily cutting through a demons flesh multiple times without showing any sign of wear. The chainsaw's brand is "Painsaw", which may be seen written on the body of the saw.