A militant culture, Sith weaponry developed quickly. The original protosaber design was upgraded, allowing for the removal of the belt-mounted powerpack and resulting in the modern lightsaber. The usage of red synth-crystals appears to have been standard amongst the Sith in this time period, at least amongst those who favored lightsabers. For the most part, many Sith Lords eschewed lightsabers in favor of . When the Sith Empire engaged the in the , the swords were extremely prevalent, but certain groups, such as the crew of the , were equipped with lightsabers. These early Sith lightsabers no doubt made their way into Jedi hands, who then copied the designs to upgrade their own weapons.
After the war, one of Kun's former acolytes, the disfigured , would be taken in by . His involvement in the war largely unknown, he became one of the founding members of Draay's , gradually taking complete control of the organization as Krynda's primary lieutenant. During this period, Haazen constructed a Sith lightsaber to replace the weapon he lost during his failed Jedi apprenticeship. However, due to his need to keep the weapon and his continuing affiliation to Sith ideals secret, he fashioned an articulated hilt that folded into a hook-shape to become the . The make of the hilt overall followed the grisly design of his prosthetics, themselves of an archaic Sith design, and he utilized the traditional bloodshine blade. This lightsaber would be kept secret for decades before finally being unveiled during , the culmination of all of Haazen's schemes. Haazen would wield the weapon against several Jedi before bestowing it on , his would-be . Draay initially operated as Haazen's willing dupe, attacking with the lightsaber before reconsidering his position and betraying Haazen. Draay disgarded the lightsaber, and it was destroyed by orbital bombardment during the destruction of the , along with Haazen himself.
During the started by , synthetic crystals and double-bladed lightsabers saw widespread usage. However, beyond the red blades, there was little to differentiate the design of these Sith lightsabers from the Jedi weapons of the period. During training, many Sith apprentices wielded when expected to engage in actual combat, until they earned their lightsabers. Students of the would perform a final test at the conclusion of their training, with one of the rewards being a unique, proper Sith lightsaber for them to keep. During the that followed, little changed in the design of Sith lightsabers, though some groups, such as the , eschewed lightsabers in favor of more covert weapons, such as .
During the reformation of the , the classical were generally swept by the wayside in favor of lightsabers. Overall, the standard Sith lightsabers of the era featured aggressive, squared-off technical designs, in contrast to the more rounded weapons favored by the Jedi. In addition to the traditional scarlet lightsaber crystals, Sith lightsabers would often have elaborate , with a double axe-head design being prevalent. This style of armament was exemplified by the class, who favored standard lightsabers but emphasized power and aggression in their use.