Unidentified Forerunner weapon

This Unidentified Weapon was an energy weapon created and used by the Forerunners during the Forerunner-Flood War.

Description
It was a white, claw shaped device that fired a bright blue bolt of energy. Upon activation the weapon generated what appeared to be a blade of some sort, capable, as previously stated, of firing bolts of energy.

Trivia

 * The hilt for the weapon appears simliar to a Constructor.
 * Along with it looking like a Constructor, the look and activation of the weapon might be where the Covenant got the idea for the Energy Sword.