From the pages of Wasyu's Encyclopedia Tenchicca--
Light Hawk Wing (OVA) [Japanese: Kou-ou-yoku]
n.: Generated and used exclusively by Tsunami, Tenchi and selected members of the Juraian royal family (with the aid of the Juraian royal trees), the Light Hawk Wing (LHW for short) is a defensive weapon capable of repelling nearly all physical attacks in existence. When operated by certain individuals, LHWs can also be used to summon destructive spheres of energy that can be hurled at an intended target.
Energy required to generate LHW is as impressive as its output power, measured in 2n energy units, where n = the number of wings being created. One of the reasons Tenchi and not Aeka boarded Ryu-oh during their initial confrontation with the Souja was because Aeka's key was not strong enough to break the seal, a seal created to prevent anyone from easily accessing LHW's offensive capability. Only a master key like Tenchi-ken could have broken the seal and take control of the LHW for offensive operations.
All Juraian spaceships are capable of generating three LHWs, but 3rd and later generation ships require joint effort to produce them. Tsunami, being the strongest ship in the universe, can produce ten LHWs, while Tenchi can create three on his own (this ability was not given to him by Tsunami). Supposedly, Ryoko, with her three gems and the proper aid of Ryo-oh-ki, can also generate LHWs.