Muramasa

A glowing blue sword that is only found in treasure chests in the Dungeon. Unlike other weapons you can hold down left mouse button and it will keep attacking.

The Muramasa has a slightly longer reach than a Phaseblade. It deals 22 damage and has a Fast attack speed. When used, it will create a small bit of light.

A good tactic is to use the weapon in conjunction with a full set of Shadow Armor and/or Feral Claws to give it an incredibly fast swipe speed which allows you to cut through virtually any enemy with ease.