The SP-B50 blaster rifle served as the armament for the Sovereign Protectors of the Sith Eternal, who guarded their supreme commander, the Dark Lord of the Sith, Darth Sidious. These were hybrid weapons, combining the functionality of a blaster with that of a vibro-active force blade. During the events of 35 ABY, these rifles were wielded against the Jedi Rey and Ben Solo, formerly known as Kylo Ren, after they betrayed Sidious. Ultimately, Rey and Ben Solo prevailed, eliminating all Sovereign Protectors and thus ceasing the employment of their specialized rifles.