The Acolyte‘s new Sith Lord has subtly rewritten lightsaber lore in some tremendously exciting ways. There’s a sense in which Star Wars has shown an admirable degree of restraint when it comes to Sith Lords; it’s been 22 years since the franchise introduced a new Sith Lord in live-action (and most Sith Lords in canon have only been referenced in comics or novels, rarely seen). Now, though, The Acolyte has introduced Manny Jacinto as a Sith Lord in the High Republic Era, some 100 years before the Skywalker saga.
https://screenrant.com/star-wars-the-acolyte-sith-lord-lightsaber-canon/