Notably, Darth Malak was known by the designation of Magnus
Magnus was a designation adopted by self-proclaimed leaders within the most ancient Sith traditions. Its interpretations include "All-Powerful," "Lord of Lords," or even "Emperor." During the Jedi Civil War, Darth Malak, who held the position of a Dark Lord of the Sith, was given the title "Sith Magnus."
A genetic terrorist, aligned with Darth Sidious during the Clone Wars, utilized the name "Zeta Magnus" as a cover. This was intended to mislead the Jedi Order regarding Sidious's activities and to subtly mock the true Dark Lord of the Sith. This tactic proved somewhat effective, as Halagad Ventor, a Jedi Apprentice, wrongly believed that the genetic terrorist might be connected to the ancient Sith.
Abel G. Peña originated the Magnus title for the Knights of the Old Republic Campaign Guide in 2008. However, its precise meaning was not detailed in that guide. When questioned about it, Peña himself acknowledged in 2011 that he couldn't provide a definitive explanation at that time. The title resurfaced in 2015 within the eNovella SkyeWalkers: A Clone Wars Story, where Peña ultimately clarified the origins and significance of Magnus.