Two lightsabers were created to serve as the weapons of Subject 1138 «Starkiller,» a clone of Darth Vader’s secret apprentice. The lightsabers were given to the clone by the Dark Lord during his training on the planet Kamino, and were used during his escape attempt immediately after Vader deemed Starkiller to be another failure in a long line of imperfect clones.
Subject 1138‘s dual weapons were constructed for the purpose of training Galen Marek‘s clone in lightsaber combat. They were part of a second series of lightsabers that Darth Vader bestowed to the clones who progressed far through their trials. As such, these lightsabers each contained a synthetic crystal which enabled them to produce a red blade. Their design was a modified version of the first set of lightsabers, many copies of which were used by the clones who were deemed as failures early in their training.
Like their counterpart weapons, Starkiller’s lightsabers were both based on a transparent hilt which displayed the blade’s energy fluctuating within. The hilts featured a set of black plates; the activator a simple red button located on a silver ring around the hilt, approximately halfway along its length. The emitters featured a slanted, wrap-around guard that was aesthetically similar to emitter shrouds, rather than the standard emitters on the first stock design.
As with his clone precursors, Starkiller was programmed with the knowledge and skills of his genetic template via memory flashes. As such, he inherited the original Starkiller’s preference for the Shien-style reversed grip, as well as the Ataru and Niman fighting styles. These combat forms ultimately enabled the clone to master the Jar’Kai technique, of which Starkiller found both strengths and weaknesses in. On the one hand, he acknowledged that the use of dual-lightsabers increased his overall abilities as a combatant, and on the other, Jar’Kai diminished the strength of his attacks since it prevented him from wielding a lightsaber with both hands.