This blade has a blue finish to it’s cutting edge, and to any creature on the Ethereal Plane it appears glaringly bright.

While holding this weapon you are able to perceive creatures on the Ethereal Plane as a faint blue specter of their true appearance.
Additionally, this weapon can affect creatures on the Ethereal Plane, such as ghosts. When you make an attack against a creature on the Ethereal Plane using this weapon you score a critical hit on a roll of 18 or higher.