After pledging himself to the Sith Lord Darth Sidious, Anakin Skywalker took the name Darth Vader but continued to use the blue-bladed lightsaber he’d fought with during the Clone Wars. He lost this weapon on Mustafar and constructed a replacement with the crimson blade favored by the Sith. Vader used his Sith lightsaber rarely but to deadly effect, as enemies of the Empire discovered.