The IKS Hidoken was a Klingon B'rel-class bird of prey commanded by General Vekor. He and his crew had stolen data from Starfleet Intelligence, regarding the Transphasic torpedo. Using the information, the crew created their own 'Klingon'-version of the torpedo and were able to thwart a Borg invasion of the Mizar II. Unfortunately, the ship was taken down with the Borg Cube to the surface of the homeworld. There were few survivors, and those that did survive - were assimilated. (Star Trek: Invasion 101)